From 0114c4d25f325784298c964c141a12cd6d60560d Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Thu, 18 Jan 2024 16:48:42 +0900
Subject: [PATCH 01/22] refactor: rename variable names

---
 system/Database/Forge.php | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/system/Database/Forge.php b/system/Database/Forge.php
index 57e43bf199fe..c23ddfad1127 100644
--- a/system/Database/Forge.php
+++ b/system/Database/Forge.php
@@ -380,15 +380,15 @@ public function addField($field)
         }
 
         if (is_array($field)) {
-            foreach ($field as $idx => $f) {
-                if (is_string($f)) {
-                    $this->addField($f);
+            foreach ($field as $name => $attributes) {
+                if (is_string($attributes)) {
+                    $this->addField($attributes);
 
                     continue;
                 }
 
-                if (is_array($f)) {
-                    $this->fields = array_merge($this->fields, [$idx => $f]);
+                if (is_array($attributes)) {
+                    $this->fields = array_merge($this->fields, [$name => $attributes]);
                 }
             }
         }
@@ -727,8 +727,8 @@ public function addColumn(string $table, $field): bool
             $field = [$field];
         }
 
-        foreach (array_keys($field) as $k) {
-            $this->addField([$k => $field[$k]]);
+        foreach (array_keys($field) as $name) {
+            $this->addField([$name => $field[$name]]);
         }
 
         $sqls = $this->_alterTable('ADD', $this->db->DBPrefix . $table, $this->_processFields());
@@ -783,8 +783,8 @@ public function modifyColumn(string $table, $field): bool
             $field = [$field];
         }
 
-        foreach (array_keys($field) as $k) {
-            $this->addField([$k => $field[$k]]);
+        foreach (array_keys($field) as $name) {
+            $this->addField([$name => $field[$name]]);
         }
 
         if ($this->fields === []) {
@@ -852,7 +852,7 @@ protected function _processFields(bool $createTable = false): array
     {
         $fields = [];
 
-        foreach ($this->fields as $key => $attributes) {
+        foreach ($this->fields as $name => $attributes) {
             if (! is_array($attributes)) {
                 $fields[] = ['_literal' => $attributes];
 
@@ -870,7 +870,7 @@ protected function _processFields(bool $createTable = false): array
             }
 
             $field = [
-                'name'           => $key,
+                'name'           => $name,
                 'new_name'       => $attributes['NAME'] ?? null,
                 'type'           => $attributes['TYPE'] ?? null,
                 'length'         => '',
@@ -1163,10 +1163,10 @@ protected function _processForeignKeys(string $table, bool $asQuery = false): ar
     {
         $errorNames = [];
 
-        foreach ($this->foreignKeys as $name) {
-            foreach ($name['field'] as $f) {
-                if (! isset($this->fields[$f])) {
-                    $errorNames[] = $f;
+        foreach ($this->foreignKeys as $fkeyInfo) {
+            foreach ($fkeyInfo['field'] as $fieldName) {
+                if (! isset($this->fields[$fieldName])) {
+                    $errorNames[] = $fieldName;
                 }
             }
         }

From 6c18480a7c8607eb5aef497b7e25c4c42250001e Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Thu, 18 Jan 2024 16:57:04 +0900
Subject: [PATCH 02/22] docs: make @var more detailed

---
 system/Database/Forge.php | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/system/Database/Forge.php b/system/Database/Forge.php
index c23ddfad1127..acb6b963bc46 100644
--- a/system/Database/Forge.php
+++ b/system/Database/Forge.php
@@ -32,7 +32,7 @@ class Forge
     /**
      * List of fields.
      *
-     * @var array
+     * @var array<string, array|string> [name => attributes]
      */
     protected $fields = [];
 
@@ -351,7 +351,7 @@ public function addUniqueKey($key, string $keyName = '')
     /**
      * Add Field
      *
-     * @param array|string $field
+     * @param array<string, array|string>|string $field
      *
      * @return Forge
      */
@@ -716,7 +716,7 @@ public function renameTable(string $tableName, string $newTableName)
     }
 
     /**
-     * @param array|string $field
+     * @param array<string, array|string>|string $field
      *
      * @throws DatabaseException
      */
@@ -772,7 +772,7 @@ public function dropColumn(string $table, $columnName)
     }
 
     /**
-     * @param array|string $field
+     * @param array<string, array|string>|string $field
      *
      * @throws DatabaseException
      */

From c452ad017bb3ffd369712608d9e60d84656c9b76 Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 15:05:35 +0900
Subject: [PATCH 03/22] docs: add PHPDocs

---
 system/Database/Forge.php | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/system/Database/Forge.php b/system/Database/Forge.php
index acb6b963bc46..a8d9efc89c30 100644
--- a/system/Database/Forge.php
+++ b/system/Database/Forge.php
@@ -518,7 +518,9 @@ public function dropForeignKey(string $table, string $foreignName)
     }
 
     /**
-     * @return mixed
+     * @param array $attributes Table attributes
+     *
+     * @return bool
      *
      * @throws DatabaseException
      */
@@ -562,6 +564,8 @@ public function createTable(string $table, bool $ifNotExists = false, array $att
     }
 
     /**
+     * @param array $attributes Table attributes
+     *
      * @return string SQL string
      *
      * @deprecated $ifNotExists is no longer used, and will be removed.

From add3e072e7b5376e1117956d36048b5c0a60949d Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 15:06:02 +0900
Subject: [PATCH 04/22] style: break long line

---
 system/Database/SQLite3/Forge.php | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/system/Database/SQLite3/Forge.php b/system/Database/SQLite3/Forge.php
index b1dcb1dd599b..3a004492244c 100644
--- a/system/Database/SQLite3/Forge.php
+++ b/system/Database/SQLite3/Forge.php
@@ -183,8 +183,11 @@ protected function _attributeType(array &$attributes)
      */
     protected function _attributeAutoIncrement(array &$attributes, array &$field)
     {
-        if (! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === true
-            && stripos($field['type'], 'int') !== false) {
+        if (
+            ! empty($attributes['AUTO_INCREMENT'])
+            && $attributes['AUTO_INCREMENT'] === true
+            && stripos($field['type'], 'int') !== false
+        ) {
             $field['type']           = 'INTEGER PRIMARY KEY';
             $field['default']        = '';
             $field['null']           = '';

From 4ac6ca513af97de726a31912f8c201e176841a4c Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 15:39:36 +0900
Subject: [PATCH 05/22] refactor: rename variable names

Variables with the same meaning have the same variable name.
Variables with different meanings are given different names.
---
 system/Database/Forge.php         | 61 ++++++++++++++++---------------
 system/Database/MySQLi/Forge.php  | 24 ++++++------
 system/Database/OCI8/Forge.php    | 28 +++++++-------
 system/Database/Postgre/Forge.php | 14 +++----
 system/Database/SQLSRV/Forge.php  | 16 ++++----
 system/Database/SQLite3/Forge.php | 20 +++++-----
 6 files changed, 82 insertions(+), 81 deletions(-)

diff --git a/system/Database/Forge.php b/system/Database/Forge.php
index a8d9efc89c30..74bb5c8fde93 100644
--- a/system/Database/Forge.php
+++ b/system/Database/Forge.php
@@ -572,22 +572,22 @@ public function createTable(string $table, bool $ifNotExists = false, array $att
      */
     protected function _createTable(string $table, bool $ifNotExists, array $attributes)
     {
-        $columns = $this->_processFields(true);
+        $processedFields = $this->_processFields(true);
 
-        for ($i = 0, $c = count($columns); $i < $c; $i++) {
-            $columns[$i] = ($columns[$i]['_literal'] !== false) ? "\n\t" . $columns[$i]['_literal']
-                : "\n\t" . $this->_processColumn($columns[$i]);
+        for ($i = 0, $c = count($processedFields); $i < $c; $i++) {
+            $processedFields[$i] = ($processedFields[$i]['_literal'] !== false) ? "\n\t" . $processedFields[$i]['_literal']
+                : "\n\t" . $this->_processColumn($processedFields[$i]);
         }
 
-        $columns = implode(',', $columns);
+        $processedFields = implode(',', $processedFields);
 
-        $columns .= $this->_processPrimaryKeys($table);
-        $columns .= current($this->_processForeignKeys($table));
+        $processedFields .= $this->_processPrimaryKeys($table);
+        $processedFields .= current($this->_processForeignKeys($table));
 
         if ($this->createTableKeys === true) {
             $indexes = current($this->_processIndexes($table));
             if (is_string($indexes)) {
-                $columns .= $indexes;
+                $processedFields .= $indexes;
             }
         }
 
@@ -595,7 +595,7 @@ protected function _createTable(string $table, bool $ifNotExists, array $attribu
             $this->createTableStr . '%s',
             'CREATE TABLE',
             $this->db->escapeIdentifiers($table),
-            $columns,
+            $processedFields,
             $this->_createTableAttributes($attributes)
         );
     }
@@ -817,30 +817,31 @@ public function modifyColumn(string $table, $field): bool
     }
 
     /**
-     * @param array|string $fields
+     * @param 'ADD'|'CHANGE'|'DROP' $alterType
+     * @param array|string          $processedFields Processed column definitions
      *
      * @return false|string|string[]
      */
-    protected function _alterTable(string $alterType, string $table, $fields)
+    protected function _alterTable(string $alterType, string $table, $processedFields)
     {
         $sql = 'ALTER TABLE ' . $this->db->escapeIdentifiers($table) . ' ';
 
         // DROP has everything it needs now.
         if ($alterType === 'DROP') {
-            if (is_string($fields)) {
-                $fields = explode(',', $fields);
+            if (is_string($processedFields)) {
+                $processedFields = explode(',', $processedFields);
             }
 
-            $fields = array_map(fn ($field) => 'DROP COLUMN ' . $this->db->escapeIdentifiers(trim($field)), $fields);
+            $processedFields = array_map(fn ($field) => 'DROP COLUMN ' . $this->db->escapeIdentifiers(trim($field)), $processedFields);
 
-            return $sql . implode(', ', $fields);
+            return $sql . implode(', ', $processedFields);
         }
 
         $sql .= ($alterType === 'ADD') ? 'ADD ' : $alterType . ' COLUMN ';
 
         $sqls = [];
 
-        foreach ($fields as $data) {
+        foreach ($processedFields as $data) {
             $sqls[] = $sql . ($data['_literal'] !== false
                 ? $data['_literal']
                 : $this->_processColumn($data));
@@ -850,15 +851,15 @@ protected function _alterTable(string $alterType, string $table, $fields)
     }
 
     /**
-     * Process fields
+     * Returns $processedFields array from $this->fields data.
      */
     protected function _processFields(bool $createTable = false): array
     {
-        $fields = [];
+        $processedFields = [];
 
         foreach ($this->fields as $name => $attributes) {
             if (! is_array($attributes)) {
-                $fields[] = ['_literal' => $attributes];
+                $processedFields[] = ['_literal' => $attributes];
 
                 continue;
             }
@@ -932,24 +933,24 @@ protected function _processFields(bool $createTable = false): array
                 $field['length'] = '(' . $attributes['CONSTRAINT'] . ')';
             }
 
-            $fields[] = $field;
+            $processedFields[] = $field;
         }
 
-        return $fields;
+        return $processedFields;
     }
 
     /**
-     * Process column
+     * Converts $processedField array to field definition string.
      */
-    protected function _processColumn(array $field): string
+    protected function _processColumn(array $processedField): string
     {
-        return $this->db->escapeIdentifiers($field['name'])
-            . ' ' . $field['type'] . $field['length']
-            . $field['unsigned']
-            . $field['default']
-            . $field['null']
-            . $field['auto_increment']
-            . $field['unique'];
+        return $this->db->escapeIdentifiers($processedField['name'])
+            . ' ' . $processedField['type'] . $processedField['length']
+            . $processedField['unsigned']
+            . $processedField['default']
+            . $processedField['null']
+            . $processedField['auto_increment']
+            . $processedField['unique'];
     }
 
     /**
diff --git a/system/Database/MySQLi/Forge.php b/system/Database/MySQLi/Forge.php
index 0d294c2d09a2..1b4f2f6b6130 100644
--- a/system/Database/MySQLi/Forge.php
+++ b/system/Database/MySQLi/Forge.php
@@ -162,23 +162,23 @@ protected function _alterTable(string $alterType, string $table, $field)
     /**
      * Process column
      */
-    protected function _processColumn(array $field): string
+    protected function _processColumn(array $processedField): string
     {
-        $extraClause = isset($field['after']) ? ' AFTER ' . $this->db->escapeIdentifiers($field['after']) : '';
+        $extraClause = isset($processedField['after']) ? ' AFTER ' . $this->db->escapeIdentifiers($processedField['after']) : '';
 
-        if (empty($extraClause) && isset($field['first']) && $field['first'] === true) {
+        if (empty($extraClause) && isset($processedField['first']) && $processedField['first'] === true) {
             $extraClause = ' FIRST';
         }
 
-        return $this->db->escapeIdentifiers($field['name'])
-                . (empty($field['new_name']) ? '' : ' ' . $this->db->escapeIdentifiers($field['new_name']))
-                . ' ' . $field['type'] . $field['length']
-                . $field['unsigned']
-                . $field['null']
-                . $field['default']
-                . $field['auto_increment']
-                . $field['unique']
-                . (empty($field['comment']) ? '' : ' COMMENT ' . $field['comment'])
+        return $this->db->escapeIdentifiers($processedField['name'])
+                . (empty($processedField['new_name']) ? '' : ' ' . $this->db->escapeIdentifiers($processedField['new_name']))
+                . ' ' . $processedField['type'] . $processedField['length']
+                . $processedField['unsigned']
+                . $processedField['null']
+                . $processedField['default']
+                . $processedField['auto_increment']
+                . $processedField['unique']
+                . (empty($processedField['comment']) ? '' : ' COMMENT ' . $processedField['comment'])
                 . $extraClause;
     }
 
diff --git a/system/Database/OCI8/Forge.php b/system/Database/OCI8/Forge.php
index 6e1e85f666a1..33f43ebf3bf3 100644
--- a/system/Database/OCI8/Forge.php
+++ b/system/Database/OCI8/Forge.php
@@ -184,26 +184,26 @@ protected function _attributeAutoIncrement(array &$attributes, array &$field)
     /**
      * Process column
      */
-    protected function _processColumn(array $field): string
+    protected function _processColumn(array $processedField): string
     {
         $constraint = '';
         // @todo: can't cover multi pattern when set type.
-        if ($field['type'] === 'VARCHAR2' && strpos($field['length'], "('") === 0) {
-            $constraint = ' CHECK(' . $this->db->escapeIdentifiers($field['name'])
-                . ' IN ' . $field['length'] . ')';
+        if ($processedField['type'] === 'VARCHAR2' && strpos($processedField['length'], "('") === 0) {
+            $constraint = ' CHECK(' . $this->db->escapeIdentifiers($processedField['name'])
+                . ' IN ' . $processedField['length'] . ')';
 
-            $field['length'] = '(' . max(array_map('mb_strlen', explode("','", mb_substr($field['length'], 2, -2)))) . ')' . $constraint;
-        } elseif (isset($this->primaryKeys['fields']) && count($this->primaryKeys['fields']) === 1 && $field['name'] === $this->primaryKeys['fields'][0]) {
-            $field['unique'] = '';
+            $processedField['length'] = '(' . max(array_map('mb_strlen', explode("','", mb_substr($processedField['length'], 2, -2)))) . ')' . $constraint;
+        } elseif (isset($this->primaryKeys['fields']) && count($this->primaryKeys['fields']) === 1 && $processedField['name'] === $this->primaryKeys['fields'][0]) {
+            $processedField['unique'] = '';
         }
 
-        return $this->db->escapeIdentifiers($field['name'])
-           . ' ' . $field['type'] . $field['length']
-           . $field['unsigned']
-           . $field['default']
-           . $field['auto_increment']
-           . $field['null']
-           . $field['unique'];
+        return $this->db->escapeIdentifiers($processedField['name'])
+           . ' ' . $processedField['type'] . $processedField['length']
+           . $processedField['unsigned']
+           . $processedField['default']
+           . $processedField['auto_increment']
+           . $processedField['null']
+           . $processedField['unique'];
     }
 
     /**
diff --git a/system/Database/Postgre/Forge.php b/system/Database/Postgre/Forge.php
index 47be1b063c8d..60eb7aba0586 100644
--- a/system/Database/Postgre/Forge.php
+++ b/system/Database/Postgre/Forge.php
@@ -134,14 +134,14 @@ protected function _alterTable(string $alterType, string $table, $field)
     /**
      * Process column
      */
-    protected function _processColumn(array $field): string
+    protected function _processColumn(array $processedField): string
     {
-        return $this->db->escapeIdentifiers($field['name'])
-            . ' ' . $field['type'] . ($field['type'] === 'text' ? '' : $field['length'])
-            . $field['default']
-            . $field['null']
-            . $field['auto_increment']
-            . $field['unique'];
+        return $this->db->escapeIdentifiers($processedField['name'])
+            . ' ' . $processedField['type'] . ($processedField['type'] === 'text' ? '' : $processedField['length'])
+            . $processedField['default']
+            . $processedField['null']
+            . $processedField['auto_increment']
+            . $processedField['unique'];
     }
 
     /**
diff --git a/system/Database/SQLSRV/Forge.php b/system/Database/SQLSRV/Forge.php
index ff1ce2e59bb9..9d7ab764e17a 100755
--- a/system/Database/SQLSRV/Forge.php
+++ b/system/Database/SQLSRV/Forge.php
@@ -287,16 +287,16 @@ protected function _processIndexes(string $table, bool $asQuery = false): array
     /**
      * Process column
      */
-    protected function _processColumn(array $field): string
+    protected function _processColumn(array $processedField): string
     {
-        return $this->db->escapeIdentifiers($field['name'])
-            . (empty($field['new_name']) ? '' : ' ' . $this->db->escapeIdentifiers($field['new_name']))
-            . ' ' . $field['type'] . ($field['type'] === 'text' ? '' : $field['length'])
-            . $field['default']
-            . $field['null']
-            . $field['auto_increment']
+        return $this->db->escapeIdentifiers($processedField['name'])
+            . (empty($processedField['new_name']) ? '' : ' ' . $this->db->escapeIdentifiers($processedField['new_name']))
+            . ' ' . $processedField['type'] . ($processedField['type'] === 'text' ? '' : $processedField['length'])
+            . $processedField['default']
+            . $processedField['null']
+            . $processedField['auto_increment']
             . ''
-            . $field['unique'];
+            . $processedField['unique'];
     }
 
     /**
diff --git a/system/Database/SQLite3/Forge.php b/system/Database/SQLite3/Forge.php
index 3a004492244c..eaa6643a85ab 100644
--- a/system/Database/SQLite3/Forge.php
+++ b/system/Database/SQLite3/Forge.php
@@ -141,19 +141,19 @@ protected function _alterTable(string $alterType, string $table, $field)
     /**
      * Process column
      */
-    protected function _processColumn(array $field): string
+    protected function _processColumn(array $processedField): string
     {
-        if ($field['type'] === 'TEXT' && strpos($field['length'], "('") === 0) {
-            $field['type'] .= ' CHECK(' . $this->db->escapeIdentifiers($field['name'])
-                . ' IN ' . $field['length'] . ')';
+        if ($processedField['type'] === 'TEXT' && strpos($processedField['length'], "('") === 0) {
+            $processedField['type'] .= ' CHECK(' . $this->db->escapeIdentifiers($processedField['name'])
+                . ' IN ' . $processedField['length'] . ')';
         }
 
-        return $this->db->escapeIdentifiers($field['name'])
-            . ' ' . $field['type']
-            . $field['auto_increment']
-            . $field['null']
-            . $field['unique']
-            . $field['default'];
+        return $this->db->escapeIdentifiers($processedField['name'])
+            . ' ' . $processedField['type']
+            . $processedField['auto_increment']
+            . $processedField['null']
+            . $processedField['unique']
+            . $processedField['default'];
     }
 
     /**

From f34fc584d94a5608d7ae9d3e46ff65e41883ff4e Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 16:00:17 +0900
Subject: [PATCH 06/22] refactor: rename variable names when DROP column

---
 system/Database/Forge.php | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/system/Database/Forge.php b/system/Database/Forge.php
index 74bb5c8fde93..3028e0e571cb 100644
--- a/system/Database/Forge.php
+++ b/system/Database/Forge.php
@@ -755,15 +755,16 @@ public function addColumn(string $table, $field): bool
     }
 
     /**
-     * @param array|string $columnName
+     * @param array|string $columnNames column names to DROP
      *
-     * @return mixed
+     * @return bool
      *
      * @throws DatabaseException
      */
-    public function dropColumn(string $table, $columnName)
+    public function dropColumn(string $table, $columnNames)
     {
-        $sql = $this->_alterTable('DROP', $this->db->DBPrefix . $table, $columnName);
+        $sql = $this->_alterTable('DROP', $this->db->DBPrefix . $table, $columnNames);
+
         if ($sql === false) {
             if ($this->db->DBDebug) {
                 throw new DatabaseException('This feature is not available for the database you are using.');
@@ -819,8 +820,10 @@ public function modifyColumn(string $table, $field): bool
     /**
      * @param 'ADD'|'CHANGE'|'DROP' $alterType
      * @param array|string          $processedFields Processed column definitions
+     *                                               or column names to DROP
      *
-     * @return false|string|string[]
+     * @return list<string>|string SQL string
+     * @phpstan-return ($alterType is 'DROP' ? string : list<string>)
      */
     protected function _alterTable(string $alterType, string $table, $processedFields)
     {
@@ -828,13 +831,15 @@ protected function _alterTable(string $alterType, string $table, $processedField
 
         // DROP has everything it needs now.
         if ($alterType === 'DROP') {
-            if (is_string($processedFields)) {
-                $processedFields = explode(',', $processedFields);
+            $columnNamesToDrop = $processedFields;
+
+            if (is_string($columnNamesToDrop)) {
+                $columnNamesToDrop = explode(',', $columnNamesToDrop);
             }
 
-            $processedFields = array_map(fn ($field) => 'DROP COLUMN ' . $this->db->escapeIdentifiers(trim($field)), $processedFields);
+            $columnNamesToDrop = array_map(fn ($field) => 'DROP COLUMN ' . $this->db->escapeIdentifiers(trim($field)), $columnNamesToDrop);
 
-            return $sql . implode(', ', $processedFields);
+            return $sql . implode(', ', $columnNamesToDrop);
         }
 
         $sql .= ($alterType === 'ADD') ? 'ADD ' : $alterType . ' COLUMN ';

From 8924cb0a10f15995907837416c81a44676b4c6dd Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 16:16:03 +0900
Subject: [PATCH 07/22] refactor: rename parameter name in _alterTable()

---
 system/Database/MySQLi/Forge.php  | 26 ++++++++-------
 system/Database/OCI8/Forge.php    | 55 ++++++++++++++++---------------
 system/Database/Postgre/Forge.php | 12 ++++---
 system/Database/SQLSRV/Forge.php  | 22 +++++++------
 system/Database/SQLite3/Forge.php | 16 +++++----
 5 files changed, 71 insertions(+), 60 deletions(-)

diff --git a/system/Database/MySQLi/Forge.php b/system/Database/MySQLi/Forge.php
index 1b4f2f6b6130..1b0ad79e7607 100644
--- a/system/Database/MySQLi/Forge.php
+++ b/system/Database/MySQLi/Forge.php
@@ -128,35 +128,37 @@ protected function _createTableAttributes(array $attributes): string
     /**
      * ALTER TABLE
      *
-     * @param string       $alterType ALTER type
-     * @param string       $table     Table name
-     * @param array|string $field     Column definition
+     * @param string       $alterType       ALTER type
+     * @param string       $table           Table name
+     * @param array|string $processedFields Processed column definitions
+     *                                      or column names to DROP
      *
-     * @return string|string[]
+     * @return list<string>|string SQL string
+     * @phpstan-return ($alterType is 'DROP' ? string : list<string>)
      */
-    protected function _alterTable(string $alterType, string $table, $field)
+    protected function _alterTable(string $alterType, string $table, $processedFields)
     {
         if ($alterType === 'DROP') {
-            return parent::_alterTable($alterType, $table, $field);
+            return parent::_alterTable($alterType, $table, $processedFields);
         }
 
         $sql = 'ALTER TABLE ' . $this->db->escapeIdentifiers($table);
 
-        foreach ($field as $i => $data) {
+        foreach ($processedFields as $i => $data) {
             if ($data['_literal'] !== false) {
-                $field[$i] = ($alterType === 'ADD') ? "\n\tADD " . $data['_literal'] : "\n\tMODIFY " . $data['_literal'];
+                $processedFields[$i] = ($alterType === 'ADD') ? "\n\tADD " . $data['_literal'] : "\n\tMODIFY " . $data['_literal'];
             } else {
                 if ($alterType === 'ADD') {
-                    $field[$i]['_literal'] = "\n\tADD ";
+                    $processedFields[$i]['_literal'] = "\n\tADD ";
                 } else {
-                    $field[$i]['_literal'] = empty($data['new_name']) ? "\n\tMODIFY " : "\n\tCHANGE ";
+                    $processedFields[$i]['_literal'] = empty($data['new_name']) ? "\n\tMODIFY " : "\n\tCHANGE ";
                 }
 
-                $field[$i] = $field[$i]['_literal'] . $this->_processColumn($field[$i]);
+                $processedFields[$i] = $processedFields[$i]['_literal'] . $this->_processColumn($processedFields[$i]);
             }
         }
 
-        return [$sql . implode(',', $field)];
+        return [$sql . implode(',', $processedFields)];
     }
 
     /**
diff --git a/system/Database/OCI8/Forge.php b/system/Database/OCI8/Forge.php
index 33f43ebf3bf3..e7688ff22f47 100644
--- a/system/Database/OCI8/Forge.php
+++ b/system/Database/OCI8/Forge.php
@@ -93,21 +93,24 @@ class Forge extends BaseForge
     /**
      * ALTER TABLE
      *
-     * @param string       $alterType ALTER type
-     * @param string       $table     Table name
-     * @param array|string $field     Column definition
+     * @param string       $alterType       ALTER type
+     * @param string       $table           Table name
+     * @param array|string $processedFields Processed column definitions
+     *                                      or column names to DROP
      *
-     * @return string|string[]
+     * @return list<string>|string SQL string
+     * @phpstan-return ($alterType is 'DROP' ? string : list<string>)
      */
-    protected function _alterTable(string $alterType, string $table, $field)
+    protected function _alterTable(string $alterType, string $table, $processedFields)
     {
         $sql = 'ALTER TABLE ' . $this->db->escapeIdentifiers($table);
 
         if ($alterType === 'DROP') {
-            $fields = array_map(fn ($field) => $this->db->escapeIdentifiers(trim($field)), is_string($field) ? explode(',', $field) : $field);
+            $fields = array_map(fn ($field) => $this->db->escapeIdentifiers(trim($processedFields)), is_string($processedFields) ? explode(',', $processedFields) : $processedFields);
 
             return $sql . ' DROP (' . implode(',', $fields) . ') CASCADE CONSTRAINT INVALIDATE';
         }
+
         if ($alterType === 'CHANGE') {
             $alterType = 'MODIFY';
         }
@@ -115,50 +118,50 @@ protected function _alterTable(string $alterType, string $table, $field)
         $nullableMap = array_column($this->db->getFieldData($table), 'nullable', 'name');
         $sqls        = [];
 
-        for ($i = 0, $c = count($field); $i < $c; $i++) {
+        for ($i = 0, $c = count($processedFields); $i < $c; $i++) {
             if ($alterType === 'MODIFY') {
                 // If a null constraint is added to a column with a null constraint,
                 // ORA-01451 will occur,
                 // so add null constraint is used only when it is different from the current null constraint.
                 // If a not null constraint is added to a column with a not null constraint,
                 // ORA-01442 will occur.
-                $wantToAddNull   = strpos($field[$i]['null'], ' NOT') === false;
-                $currentNullable = $nullableMap[$field[$i]['name']];
+                $wantToAddNull   = strpos($processedFields[$i]['null'], ' NOT') === false;
+                $currentNullable = $nullableMap[$processedFields[$i]['name']];
 
                 if ($wantToAddNull === true && $currentNullable === true) {
-                    $field[$i]['null'] = '';
-                } elseif ($field[$i]['null'] === '' && $currentNullable === false) {
+                    $processedFields[$i]['null'] = '';
+                } elseif ($processedFields[$i]['null'] === '' && $currentNullable === false) {
                     // Nullable by default
-                    $field[$i]['null'] = ' NULL';
+                    $processedFields[$i]['null'] = ' NULL';
                 } elseif ($wantToAddNull === false && $currentNullable === false) {
-                    $field[$i]['null'] = '';
+                    $processedFields[$i]['null'] = '';
                 }
             }
 
-            if ($field[$i]['_literal'] !== false) {
-                $field[$i] = "\n\t" . $field[$i]['_literal'];
+            if ($processedFields[$i]['_literal'] !== false) {
+                $processedFields[$i] = "\n\t" . $processedFields[$i]['_literal'];
             } else {
-                $field[$i]['_literal'] = "\n\t" . $this->_processColumn($field[$i]);
+                $processedFields[$i]['_literal'] = "\n\t" . $this->_processColumn($processedFields[$i]);
 
-                if (! empty($field[$i]['comment'])) {
+                if (! empty($processedFields[$i]['comment'])) {
                     $sqls[] = 'COMMENT ON COLUMN '
-                        . $this->db->escapeIdentifiers($table) . '.' . $this->db->escapeIdentifiers($field[$i]['name'])
-                        . ' IS ' . $field[$i]['comment'];
+                        . $this->db->escapeIdentifiers($table) . '.' . $this->db->escapeIdentifiers($processedFields[$i]['name'])
+                        . ' IS ' . $processedFields[$i]['comment'];
                 }
 
-                if ($alterType === 'MODIFY' && ! empty($field[$i]['new_name'])) {
-                    $sqls[] = $sql . ' RENAME COLUMN ' . $this->db->escapeIdentifiers($field[$i]['name'])
-                        . ' TO ' . $this->db->escapeIdentifiers($field[$i]['new_name']);
+                if ($alterType === 'MODIFY' && ! empty($processedFields[$i]['new_name'])) {
+                    $sqls[] = $sql . ' RENAME COLUMN ' . $this->db->escapeIdentifiers($processedFields[$i]['name'])
+                        . ' TO ' . $this->db->escapeIdentifiers($processedFields[$i]['new_name']);
                 }
 
-                $field[$i] = "\n\t" . $field[$i]['_literal'];
+                $processedFields[$i] = "\n\t" . $processedFields[$i]['_literal'];
             }
         }
 
         $sql .= ' ' . $alterType . ' ';
-        $sql .= count($field) === 1
-                ? $field[0]
-                : '(' . implode(',', $field) . ')';
+        $sql .= count($processedFields) === 1
+                ? $processedFields[0]
+                : '(' . implode(',', $processedFields) . ')';
 
         // RENAME COLUMN must be executed after MODIFY
         array_unshift($sqls, $sql);
diff --git a/system/Database/Postgre/Forge.php b/system/Database/Postgre/Forge.php
index 60eb7aba0586..e3cf2ee63fab 100644
--- a/system/Database/Postgre/Forge.php
+++ b/system/Database/Postgre/Forge.php
@@ -81,20 +81,22 @@ protected function _createTableAttributes(array $attributes): string
     }
 
     /**
-     * @param array|string $field
+     * @param array|string $processedFields Processed column definitions
+     *                                      or column names to DROP
      *
-     * @return array|bool|string
+     * @return false|list<string>|string SQL string or false
+     * @phpstan-return ($alterType is 'DROP' ? string : list<string>|false)
      */
-    protected function _alterTable(string $alterType, string $table, $field)
+    protected function _alterTable(string $alterType, string $table, $processedFields)
     {
         if (in_array($alterType, ['DROP', 'ADD'], true)) {
-            return parent::_alterTable($alterType, $table, $field);
+            return parent::_alterTable($alterType, $table, $processedFields);
         }
 
         $sql  = 'ALTER TABLE ' . $this->db->escapeIdentifiers($table);
         $sqls = [];
 
-        foreach ($field as $data) {
+        foreach ($processedFields as $data) {
             if ($data['_literal'] !== false) {
                 return false;
             }
diff --git a/system/Database/SQLSRV/Forge.php b/system/Database/SQLSRV/Forge.php
index 9d7ab764e17a..38740b57e640 100755
--- a/system/Database/SQLSRV/Forge.php
+++ b/system/Database/SQLSRV/Forge.php
@@ -126,11 +126,13 @@ protected function _createTableAttributes(array $attributes): string
     }
 
     /**
-     * @param array|string $field
+     * @param array|string $processedFields Processed column definitions
+     *                                      or column names to DROP
      *
-     * @return false|string|string[]
+     * @return list<string>|string SQL string
+     * @phpstan-return ($alterType is 'DROP' ? string : list<string>)
      */
-    protected function _alterTable(string $alterType, string $table, $field)
+    protected function _alterTable(string $alterType, string $table, $processedFields)
     {
         // Handle DROP here
         if ($alterType === 'DROP') {
@@ -138,11 +140,11 @@ protected function _alterTable(string $alterType, string $table, $field)
             $indexData = $this->db->getIndexData($table);
 
             foreach ($indexData as $index) {
-                if (is_string($field)) {
-                    $field = explode(',', $field);
+                if (is_string($processedFields)) {
+                    $processedFields = explode(',', $processedFields);
                 }
 
-                $fld = array_intersect($field, $index->fields);
+                $fld = array_intersect($processedFields, $index->fields);
 
                 // Drop index if field is part of an index
                 if ($fld !== []) {
@@ -153,7 +155,7 @@ protected function _alterTable(string $alterType, string $table, $field)
             $fullTable = $this->db->escapeIdentifiers($this->db->schema) . '.' . $this->db->escapeIdentifiers($table);
 
             // Drop default constraints
-            $fields = implode(',', $this->db->escape((array) $field));
+            $fields = implode(',', $this->db->escape((array) $processedFields));
 
             $sql = <<<SQL
                 SELECT name
@@ -170,7 +172,7 @@ protected function _alterTable(string $alterType, string $table, $field)
 
             $sql = 'ALTER TABLE ' . $fullTable . ' DROP ';
 
-            $fields = array_map(static fn ($item) => 'COLUMN [' . trim($item) . ']', (array) $field);
+            $fields = array_map(static fn ($item) => 'COLUMN [' . trim($item) . ']', (array) $processedFields);
 
             return $sql . implode(',', $fields);
         }
@@ -181,14 +183,14 @@ protected function _alterTable(string $alterType, string $table, $field)
         $sqls = [];
 
         if ($alterType === 'ADD') {
-            foreach ($field as $data) {
+            foreach ($processedFields as $data) {
                 $sqls[] = $sql . ($data['_literal'] !== false ? $data['_literal'] : $this->_processColumn($data));
             }
 
             return $sqls;
         }
 
-        foreach ($field as $data) {
+        foreach ($processedFields as $data) {
             if ($data['_literal'] !== false) {
                 return false;
             }
diff --git a/system/Database/SQLite3/Forge.php b/system/Database/SQLite3/Forge.php
index eaa6643a85ab..e6d14440108b 100644
--- a/system/Database/SQLite3/Forge.php
+++ b/system/Database/SQLite3/Forge.php
@@ -109,32 +109,34 @@ public function dropDatabase(string $dbName): bool
     }
 
     /**
-     * @param array|string $field
+     * @param array|string $processedFields Processed column definitions
+     *                                      or column names to DROP
      *
      * @return array|string|null
+     * @return list<string>|string|null SQL string or null
      */
-    protected function _alterTable(string $alterType, string $table, $field)
+    protected function _alterTable(string $alterType, string $table, $processedFields)
     {
         switch ($alterType) {
             case 'DROP':
                 $sqlTable = new Table($this->db, $this);
 
                 $sqlTable->fromTable($table)
-                    ->dropColumn($field)
+                    ->dropColumn($processedFields)
                     ->run();
 
-                return '';
+                return ''; // Why empty string?
 
             case 'CHANGE':
                 (new Table($this->db, $this))
                     ->fromTable($table)
-                    ->modifyColumn($field)
+                    ->modifyColumn($processedFields)
                     ->run();
 
-                return null;
+                return null; // Why null?
 
             default:
-                return parent::_alterTable($alterType, $table, $field);
+                return parent::_alterTable($alterType, $table, $processedFields);
         }
     }
 

From 145e89a828f89581ff629e6bfbc52b9c13b62054 Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 16:24:01 +0900
Subject: [PATCH 08/22] docs: add @TODO

---
 system/Database/SQLite3/Forge.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/system/Database/SQLite3/Forge.php b/system/Database/SQLite3/Forge.php
index e6d14440108b..abe13d0035ec 100644
--- a/system/Database/SQLite3/Forge.php
+++ b/system/Database/SQLite3/Forge.php
@@ -130,7 +130,7 @@ protected function _alterTable(string $alterType, string $table, $processedField
             case 'CHANGE':
                 (new Table($this->db, $this))
                     ->fromTable($table)
-                    ->modifyColumn($processedFields)
+                    ->modifyColumn($processedFields) // @TODO Bug: should be NOT processed fields
                     ->run();
 
                 return null; // Why null?

From a33ff9c17b30e0bcb94ac16193d2ef6ba2b28d56 Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 16:24:19 +0900
Subject: [PATCH 09/22] docs: add PHPDoc types

---
 system/Database/SQLite3/Table.php | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/system/Database/SQLite3/Table.php b/system/Database/SQLite3/Table.php
index 77fd8699459f..1b1bf4f01c51 100644
--- a/system/Database/SQLite3/Table.php
+++ b/system/Database/SQLite3/Table.php
@@ -28,7 +28,7 @@ class Table
     /**
      * All of the fields this table represents.
      *
-     * @var array<string, array<string, bool|int|string|null>>
+     * @var array<string, array<string, bool|int|string|null>> [name => attributes]
      */
     protected $fields = [];
 
@@ -156,7 +156,7 @@ public function run(): bool
     /**
      * Drops columns from the table.
      *
-     * @param array|string $columns
+     * @param list<string>|string $columns Column names to drop.
      *
      * @return Table
      */
@@ -180,6 +180,8 @@ public function dropColumn($columns)
      * Modifies a field, including changing data type,
      * renaming, etc.
      *
+     * @param array<string, array<string, bool|int|string|null>> $fields [name => attributes]
+     *
      * @return Table
      */
     public function modifyColumn(array $fields)

From 3f56cc55c45afe082e232a19ff32d7dedb12977c Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 16:29:52 +0900
Subject: [PATCH 10/22] refactor: replace $data with $field

---
 system/Database/Forge.php         |  8 +++----
 system/Database/MySQLi/Forge.php  |  8 +++----
 system/Database/Postgre/Forge.php | 32 +++++++++++++--------------
 system/Database/SQLSRV/Forge.php  | 36 +++++++++++++++----------------
 4 files changed, 42 insertions(+), 42 deletions(-)

diff --git a/system/Database/Forge.php b/system/Database/Forge.php
index 3028e0e571cb..4d5ef643c34b 100644
--- a/system/Database/Forge.php
+++ b/system/Database/Forge.php
@@ -846,10 +846,10 @@ protected function _alterTable(string $alterType, string $table, $processedField
 
         $sqls = [];
 
-        foreach ($processedFields as $data) {
-            $sqls[] = $sql . ($data['_literal'] !== false
-                ? $data['_literal']
-                : $this->_processColumn($data));
+        foreach ($processedFields as $field) {
+            $sqls[] = $sql . ($field['_literal'] !== false
+                ? $field['_literal']
+                : $this->_processColumn($field));
         }
 
         return $sqls;
diff --git a/system/Database/MySQLi/Forge.php b/system/Database/MySQLi/Forge.php
index 1b0ad79e7607..b1beba2a9dd2 100644
--- a/system/Database/MySQLi/Forge.php
+++ b/system/Database/MySQLi/Forge.php
@@ -144,14 +144,14 @@ protected function _alterTable(string $alterType, string $table, $processedField
 
         $sql = 'ALTER TABLE ' . $this->db->escapeIdentifiers($table);
 
-        foreach ($processedFields as $i => $data) {
-            if ($data['_literal'] !== false) {
-                $processedFields[$i] = ($alterType === 'ADD') ? "\n\tADD " . $data['_literal'] : "\n\tMODIFY " . $data['_literal'];
+        foreach ($processedFields as $i => $field) {
+            if ($field['_literal'] !== false) {
+                $processedFields[$i] = ($alterType === 'ADD') ? "\n\tADD " . $field['_literal'] : "\n\tMODIFY " . $field['_literal'];
             } else {
                 if ($alterType === 'ADD') {
                     $processedFields[$i]['_literal'] = "\n\tADD ";
                 } else {
-                    $processedFields[$i]['_literal'] = empty($data['new_name']) ? "\n\tMODIFY " : "\n\tCHANGE ";
+                    $processedFields[$i]['_literal'] = empty($field['new_name']) ? "\n\tMODIFY " : "\n\tCHANGE ";
                 }
 
                 $processedFields[$i] = $processedFields[$i]['_literal'] . $this->_processColumn($processedFields[$i]);
diff --git a/system/Database/Postgre/Forge.php b/system/Database/Postgre/Forge.php
index e3cf2ee63fab..ee7583642684 100644
--- a/system/Database/Postgre/Forge.php
+++ b/system/Database/Postgre/Forge.php
@@ -96,37 +96,37 @@ protected function _alterTable(string $alterType, string $table, $processedField
         $sql  = 'ALTER TABLE ' . $this->db->escapeIdentifiers($table);
         $sqls = [];
 
-        foreach ($processedFields as $data) {
-            if ($data['_literal'] !== false) {
+        foreach ($processedFields as $field) {
+            if ($field['_literal'] !== false) {
                 return false;
             }
 
-            if (version_compare($this->db->getVersion(), '8', '>=') && isset($data['type'])) {
-                $sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escapeIdentifiers($data['name'])
-                    . " TYPE {$data['type']}{$data['length']}";
+            if (version_compare($this->db->getVersion(), '8', '>=') && isset($field['type'])) {
+                $sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escapeIdentifiers($field['name'])
+                    . " TYPE {$field['type']}{$field['length']}";
             }
 
-            if (! empty($data['default'])) {
-                $sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escapeIdentifiers($data['name'])
-                    . " SET DEFAULT {$data['default']}";
+            if (! empty($field['default'])) {
+                $sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escapeIdentifiers($field['name'])
+                    . " SET DEFAULT {$field['default']}";
             }
 
             $nullable = true; // Nullable by default.
-            if (isset($data['null']) && ($data['null'] === false || $data['null'] === ' NOT ' . $this->null)) {
+            if (isset($field['null']) && ($field['null'] === false || $field['null'] === ' NOT ' . $this->null)) {
                 $nullable = false;
             }
-            $sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escapeIdentifiers($data['name'])
+            $sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escapeIdentifiers($field['name'])
                 . ($nullable === true ? ' DROP' : ' SET') . ' NOT NULL';
 
-            if (! empty($data['new_name'])) {
-                $sqls[] = $sql . ' RENAME COLUMN ' . $this->db->escapeIdentifiers($data['name'])
-                    . ' TO ' . $this->db->escapeIdentifiers($data['new_name']);
+            if (! empty($field['new_name'])) {
+                $sqls[] = $sql . ' RENAME COLUMN ' . $this->db->escapeIdentifiers($field['name'])
+                    . ' TO ' . $this->db->escapeIdentifiers($field['new_name']);
             }
 
-            if (! empty($data['comment'])) {
+            if (! empty($field['comment'])) {
                 $sqls[] = 'COMMENT ON COLUMN' . $this->db->escapeIdentifiers($table)
-                    . '.' . $this->db->escapeIdentifiers($data['name'])
-                    . " IS {$data['comment']}";
+                    . '.' . $this->db->escapeIdentifiers($field['name'])
+                    . " IS {$field['comment']}";
             }
         }
 
diff --git a/system/Database/SQLSRV/Forge.php b/system/Database/SQLSRV/Forge.php
index 38740b57e640..1e6db4b3c081 100755
--- a/system/Database/SQLSRV/Forge.php
+++ b/system/Database/SQLSRV/Forge.php
@@ -183,45 +183,45 @@ protected function _alterTable(string $alterType, string $table, $processedField
         $sqls = [];
 
         if ($alterType === 'ADD') {
-            foreach ($processedFields as $data) {
-                $sqls[] = $sql . ($data['_literal'] !== false ? $data['_literal'] : $this->_processColumn($data));
+            foreach ($processedFields as $field) {
+                $sqls[] = $sql . ($field['_literal'] !== false ? $field['_literal'] : $this->_processColumn($field));
             }
 
             return $sqls;
         }
 
-        foreach ($processedFields as $data) {
-            if ($data['_literal'] !== false) {
+        foreach ($processedFields as $field) {
+            if ($field['_literal'] !== false) {
                 return false;
             }
 
-            if (isset($data['type'])) {
-                $sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escapeIdentifiers($data['name'])
-                    . " {$data['type']}{$data['length']}";
+            if (isset($field['type'])) {
+                $sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escapeIdentifiers($field['name'])
+                    . " {$field['type']}{$field['length']}";
             }
 
-            if (! empty($data['default'])) {
-                $sqls[] = $sql . ' ALTER COLUMN ADD CONSTRAINT ' . $this->db->escapeIdentifiers($data['name']) . '_def'
-                    . " DEFAULT {$data['default']} FOR " . $this->db->escapeIdentifiers($data['name']);
+            if (! empty($field['default'])) {
+                $sqls[] = $sql . ' ALTER COLUMN ADD CONSTRAINT ' . $this->db->escapeIdentifiers($field['name']) . '_def'
+                    . " DEFAULT {$field['default']} FOR " . $this->db->escapeIdentifiers($field['name']);
             }
 
             $nullable = true; // Nullable by default.
-            if (isset($data['null']) && ($data['null'] === false || $data['null'] === ' NOT ' . $this->null)) {
+            if (isset($field['null']) && ($field['null'] === false || $field['null'] === ' NOT ' . $this->null)) {
                 $nullable = false;
             }
-            $sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escapeIdentifiers($data['name'])
-                . " {$data['type']}{$data['length']} " . ($nullable === true ? '' : 'NOT') . ' NULL';
+            $sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escapeIdentifiers($field['name'])
+                . " {$field['type']}{$field['length']} " . ($nullable === true ? '' : 'NOT') . ' NULL';
 
-            if (! empty($data['comment'])) {
+            if (! empty($field['comment'])) {
                 $sqls[] = 'EXEC sys.sp_addextendedproperty '
-                    . "@name=N'Caption', @value=N'" . $data['comment'] . "' , "
+                    . "@name=N'Caption', @value=N'" . $field['comment'] . "' , "
                     . "@level0type=N'SCHEMA',@level0name=N'" . $this->db->schema . "', "
                     . "@level1type=N'TABLE',@level1name=N'" . $this->db->escapeIdentifiers($table) . "', "
-                    . "@level2type=N'COLUMN',@level2name=N'" . $this->db->escapeIdentifiers($data['name']) . "'";
+                    . "@level2type=N'COLUMN',@level2name=N'" . $this->db->escapeIdentifiers($field['name']) . "'";
             }
 
-            if (! empty($data['new_name'])) {
-                $sqls[] = "EXEC sp_rename  '[" . $this->db->schema . '].[' . $table . '].[' . $data['name'] . "]' , '" . $data['new_name'] . "', 'COLUMN';";
+            if (! empty($field['new_name'])) {
+                $sqls[] = "EXEC sp_rename  '[" . $this->db->schema . '].[' . $table . '].[' . $field['name'] . "]' , '" . $field['new_name'] . "', 'COLUMN';";
             }
         }
 

From 601ec5895148b2d8d501eed2f31df8cce19d027d Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 16:39:25 +0900
Subject: [PATCH 11/22] docs: fix @phpstan-return

---
 phpstan-baseline.php              | 10 ----------
 system/Database/Forge.php         |  4 ++--
 system/Database/SQLSRV/Forge.php  |  4 ++--
 system/Database/SQLite3/Forge.php |  1 +
 4 files changed, 5 insertions(+), 14 deletions(-)

diff --git a/phpstan-baseline.php b/phpstan-baseline.php
index 9aa75c0b204b..48585d6fd969 100644
--- a/phpstan-baseline.php
+++ b/phpstan-baseline.php
@@ -1451,11 +1451,6 @@
 	'count' => 1,
 	'path' => __DIR__ . '/system/Database/Postgre/Forge.php',
 ];
-$ignoreErrors[] = [
-	'message' => '#^Return type \\(array\\|bool\\|string\\) of method CodeIgniter\\\\Database\\\\Postgre\\\\Forge\\:\\:_alterTable\\(\\) should be covariant with return type \\(array\\<string\\>\\|string\\|false\\) of method CodeIgniter\\\\Database\\\\Forge\\:\\:_alterTable\\(\\)$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Database/Postgre/Forge.php',
-];
 $ignoreErrors[] = [
 	'message' => '#^Construct empty\\(\\) is not allowed\\. Use more strict comparison\\.$#',
 	'count' => 1,
@@ -1656,11 +1651,6 @@
 	'count' => 1,
 	'path' => __DIR__ . '/system/Database/SQLite3/Forge.php',
 ];
-$ignoreErrors[] = [
-	'message' => '#^Return type \\(array\\|string\\|null\\) of method CodeIgniter\\\\Database\\\\SQLite3\\\\Forge\\:\\:_alterTable\\(\\) should be covariant with return type \\(array\\<string\\>\\|string\\|false\\) of method CodeIgniter\\\\Database\\\\Forge\\:\\:_alterTable\\(\\)$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Database/SQLite3/Forge.php',
-];
 $ignoreErrors[] = [
 	'message' => '#^Return type \\(SQLite3Result\\|false\\) of method CodeIgniter\\\\Database\\\\SQLite3\\\\PreparedQuery\\:\\:_getResult\\(\\) should be covariant with return type \\(object\\|resource\\|null\\) of method CodeIgniter\\\\Database\\\\BasePreparedQuery\\<SQLite3,SQLite3Stmt,SQLite3Result\\>\\:\\:_getResult\\(\\)$#',
 	'count' => 1,
diff --git a/system/Database/Forge.php b/system/Database/Forge.php
index 4d5ef643c34b..497185aba6ec 100644
--- a/system/Database/Forge.php
+++ b/system/Database/Forge.php
@@ -822,8 +822,8 @@ public function modifyColumn(string $table, $field): bool
      * @param array|string          $processedFields Processed column definitions
      *                                               or column names to DROP
      *
-     * @return list<string>|string SQL string
-     * @phpstan-return ($alterType is 'DROP' ? string : list<string>)
+     * @return false|list<string>|string|null SQL string
+     * @phpstan-return ($alterType is 'DROP' ? string : list<string>|false|null)
      */
     protected function _alterTable(string $alterType, string $table, $processedFields)
     {
diff --git a/system/Database/SQLSRV/Forge.php b/system/Database/SQLSRV/Forge.php
index 1e6db4b3c081..08e7952e7a0b 100755
--- a/system/Database/SQLSRV/Forge.php
+++ b/system/Database/SQLSRV/Forge.php
@@ -129,8 +129,8 @@ protected function _createTableAttributes(array $attributes): string
      * @param array|string $processedFields Processed column definitions
      *                                      or column names to DROP
      *
-     * @return list<string>|string SQL string
-     * @phpstan-return ($alterType is 'DROP' ? string : list<string>)
+     * @return false|list<string>|string SQL string or false
+     * @phpstan-return ($alterType is 'DROP' ? string : list<string>|false)
      */
     protected function _alterTable(string $alterType, string $table, $processedFields)
     {
diff --git a/system/Database/SQLite3/Forge.php b/system/Database/SQLite3/Forge.php
index abe13d0035ec..3e34fa535f85 100644
--- a/system/Database/SQLite3/Forge.php
+++ b/system/Database/SQLite3/Forge.php
@@ -114,6 +114,7 @@ public function dropDatabase(string $dbName): bool
      *
      * @return array|string|null
      * @return list<string>|string|null SQL string or null
+     * @phpstan-return ($alterType is 'DROP' ? string : list<string>|false|null)
      */
     protected function _alterTable(string $alterType, string $table, $processedFields)
     {

From e14ca8be383a89022a94bda3bf48c6367058c8b8 Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 16:58:04 +0900
Subject: [PATCH 12/22] style: break long line

---
 system/Database/OCI8/Forge.php | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/system/Database/OCI8/Forge.php b/system/Database/OCI8/Forge.php
index e7688ff22f47..efef8245bb67 100644
--- a/system/Database/OCI8/Forge.php
+++ b/system/Database/OCI8/Forge.php
@@ -106,7 +106,10 @@ protected function _alterTable(string $alterType, string $table, $processedField
         $sql = 'ALTER TABLE ' . $this->db->escapeIdentifiers($table);
 
         if ($alterType === 'DROP') {
-            $fields = array_map(fn ($field) => $this->db->escapeIdentifiers(trim($processedFields)), is_string($processedFields) ? explode(',', $processedFields) : $processedFields);
+            $fields = array_map(
+                fn ($field) => $this->db->escapeIdentifiers(trim($processedFields)),
+                is_string($processedFields) ? explode(',', $processedFields) : $processedFields
+            );
 
             return $sql . ' DROP (' . implode(',', $fields) . ') CASCADE CONSTRAINT INVALIDATE';
         }

From bf30645d2f6d058dbed61312495d376d3fcced4f Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 17:01:08 +0900
Subject: [PATCH 13/22] fix: incorrect refactoring

---
 system/Database/OCI8/Forge.php | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/system/Database/OCI8/Forge.php b/system/Database/OCI8/Forge.php
index efef8245bb67..232bdcf2721e 100644
--- a/system/Database/OCI8/Forge.php
+++ b/system/Database/OCI8/Forge.php
@@ -106,9 +106,11 @@ protected function _alterTable(string $alterType, string $table, $processedField
         $sql = 'ALTER TABLE ' . $this->db->escapeIdentifiers($table);
 
         if ($alterType === 'DROP') {
+            $columnNamesToDrop = $processedFields;
+
             $fields = array_map(
-                fn ($field) => $this->db->escapeIdentifiers(trim($processedFields)),
-                is_string($processedFields) ? explode(',', $processedFields) : $processedFields
+                fn ($field) => $this->db->escapeIdentifiers(trim($field)),
+                is_string($columnNamesToDrop) ? explode(',', $columnNamesToDrop) : $columnNamesToDrop
             );
 
             return $sql . ' DROP (' . implode(',', $fields) . ') CASCADE CONSTRAINT INVALIDATE';

From 4d930fbc441a9a3cc19df40266ee4f45a719b017 Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 17:09:23 +0900
Subject: [PATCH 14/22] docs: fix @phpstan-return

---
 system/Database/SQLite3/Forge.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/system/Database/SQLite3/Forge.php b/system/Database/SQLite3/Forge.php
index 3e34fa535f85..f9b6b8af23c6 100644
--- a/system/Database/SQLite3/Forge.php
+++ b/system/Database/SQLite3/Forge.php
@@ -114,7 +114,7 @@ public function dropDatabase(string $dbName): bool
      *
      * @return array|string|null
      * @return list<string>|string|null SQL string or null
-     * @phpstan-return ($alterType is 'DROP' ? string : list<string>|false|null)
+     * @phpstan-return ($alterType is 'DROP' ? string : list<string>|null)
      */
     protected function _alterTable(string $alterType, string $table, $processedFields)
     {

From 1dd2e965c33e8daf74b4f0a61d0389003eaa31d3 Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 18:40:01 +0900
Subject: [PATCH 15/22] refactor: rename parameter name in
 Table::modifyColumn()

---
 system/Database/SQLite3/Table.php | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/system/Database/SQLite3/Table.php b/system/Database/SQLite3/Table.php
index 1b1bf4f01c51..620d28464738 100644
--- a/system/Database/SQLite3/Table.php
+++ b/system/Database/SQLite3/Table.php
@@ -177,16 +177,15 @@ public function dropColumn($columns)
     }
 
     /**
-     * Modifies a field, including changing data type,
-     * renaming, etc.
+     * Modifies a field, including changing data type, renaming, etc.
      *
-     * @param array<string, array<string, bool|int|string|null>> $fields [name => attributes]
+     * @param list<array<string, bool|int|string|null>> $fieldsToModify
      *
      * @return Table
      */
-    public function modifyColumn(array $fields)
+    public function modifyColumn(array $fieldsToModify)
     {
-        foreach ($fields as $field) {
+        foreach ($fieldsToModify as $field) {
             $oldName = $field['name'];
             unset($field['name']);
 

From f097aeb10faff92b0fca066d393e3cff329f3387 Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 20:29:57 +0900
Subject: [PATCH 16/22] refactor: replace $field with $fields

---
 system/Database/Forge.php | 38 +++++++++++++++++++-------------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/system/Database/Forge.php b/system/Database/Forge.php
index 497185aba6ec..5a3600e3388f 100644
--- a/system/Database/Forge.php
+++ b/system/Database/Forge.php
@@ -351,14 +351,14 @@ public function addUniqueKey($key, string $keyName = '')
     /**
      * Add Field
      *
-     * @param array<string, array|string>|string $field
+     * @param array<string, array|string>|string $fields Field array or Field string
      *
      * @return Forge
      */
-    public function addField($field)
+    public function addField($fields)
     {
-        if (is_string($field)) {
-            if ($field === 'id') {
+        if (is_string($fields)) {
+            if ($fields === 'id') {
                 $this->addField([
                     'id' => [
                         'type'           => 'INT',
@@ -368,19 +368,19 @@ public function addField($field)
                 ]);
                 $this->addKey('id', true);
             } else {
-                if (strpos($field, ' ') === false) {
+                if (strpos($fields, ' ') === false) {
                     throw new InvalidArgumentException('Field information is required for that operation.');
                 }
 
-                $fieldName = explode(' ', $field, 2)[0];
+                $fieldName = explode(' ', $fields, 2)[0];
                 $fieldName = trim($fieldName, '`\'"');
 
-                $this->fields[$fieldName] = $field;
+                $this->fields[$fieldName] = $fields;
             }
         }
 
-        if (is_array($field)) {
-            foreach ($field as $name => $attributes) {
+        if (is_array($fields)) {
+            foreach ($fields as $name => $attributes) {
                 if (is_string($attributes)) {
                     $this->addField($attributes);
 
@@ -720,19 +720,19 @@ public function renameTable(string $tableName, string $newTableName)
     }
 
     /**
-     * @param array<string, array|string>|string $field
+     * @param array<string, array|string>|string $fields Field array or Field string
      *
      * @throws DatabaseException
      */
-    public function addColumn(string $table, $field): bool
+    public function addColumn(string $table, $fields): bool
     {
         // Work-around for literal column definitions
         if (! is_array($field)) {
-            $field = [$field];
+            $fields = [$fields];
         }
 
-        foreach (array_keys($field) as $name) {
-            $this->addField([$name => $field[$name]]);
+        foreach (array_keys($fields) as $name) {
+            $this->addField([$name => $fields[$name]]);
         }
 
         $sqls = $this->_alterTable('ADD', $this->db->DBPrefix . $table, $this->_processFields());
@@ -777,19 +777,19 @@ public function dropColumn(string $table, $columnNames)
     }
 
     /**
-     * @param array<string, array|string>|string $field
+     * @param array<string, array|string>|string $fields Field array or Field string
      *
      * @throws DatabaseException
      */
-    public function modifyColumn(string $table, $field): bool
+    public function modifyColumn(string $table, $fields): bool
     {
         // Work-around for literal column definitions
         if (! is_array($field)) {
-            $field = [$field];
+            $fields = [$fields];
         }
 
-        foreach (array_keys($field) as $name) {
-            $this->addField([$name => $field[$name]]);
+        foreach (array_keys($fields) as $name) {
+            $this->addField([$name => $fields[$name]]);
         }
 
         if ($this->fields === []) {

From b9c063f593c5217407d8952c1cdf0240daebb5bb Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 20:30:31 +0900
Subject: [PATCH 17/22] style: break long line

---
 system/Database/Forge.php | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/system/Database/Forge.php b/system/Database/Forge.php
index 5a3600e3388f..b42995f90a05 100644
--- a/system/Database/Forge.php
+++ b/system/Database/Forge.php
@@ -404,8 +404,14 @@ public function addField($fields)
      *
      * @throws DatabaseException
      */
-    public function addForeignKey($fieldName = '', string $tableName = '', $tableField = '', string $onUpdate = '', string $onDelete = '', string $fkName = ''): Forge
-    {
+    public function addForeignKey(
+        $fieldName = '',
+        string $tableName = '',
+        $tableField = '',
+        string $onUpdate = '',
+        string $onDelete = '',
+        string $fkName = ''
+    ): Forge {
         $fieldName  = (array) $fieldName;
         $tableField = (array) $tableField;
 

From 3d4e12b6b6e979fe5ccb634fd50acd038426d707 Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 20:31:01 +0900
Subject: [PATCH 18/22] style: add empty lines

---
 system/Database/Forge.php | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/system/Database/Forge.php b/system/Database/Forge.php
index b42995f90a05..bf19980240ef 100644
--- a/system/Database/Forge.php
+++ b/system/Database/Forge.php
@@ -434,8 +434,9 @@ public function addForeignKey(
      */
     public function dropKey(string $table, string $keyName, bool $prefixKeyName = true): bool
     {
-        $keyName             = $this->db->escapeIdentifiers(($prefixKeyName === true ? $this->db->DBPrefix : '') . $keyName);
-        $table               = $this->db->escapeIdentifiers($this->db->DBPrefix . $table);
+        $keyName = $this->db->escapeIdentifiers(($prefixKeyName === true ? $this->db->DBPrefix : '') . $keyName);
+        $table   = $this->db->escapeIdentifiers($this->db->DBPrefix . $table);
+
         $dropKeyAsConstraint = $this->dropKeyAsConstraint($table, $keyName);
 
         if ($dropKeyAsConstraint === true) {
@@ -743,6 +744,7 @@ public function addColumn(string $table, $fields): bool
 
         $sqls = $this->_alterTable('ADD', $this->db->DBPrefix . $table, $this->_processFields());
         $this->reset();
+
         if ($sqls === false) {
             if ($this->db->DBDebug) {
                 throw new DatabaseException('This feature is not available for the database you are using.');
@@ -804,6 +806,7 @@ public function modifyColumn(string $table, $fields): bool
 
         $sqls = $this->_alterTable('CHANGE', $this->db->DBPrefix . $table, $this->_processFields());
         $this->reset();
+
         if ($sqls === false) {
             if ($this->db->DBDebug) {
                 throw new DatabaseException('This feature is not available for the database you are using.');

From b8db96a7ca0bc2bc1b0d83ab7b7612881f845335 Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 20:31:17 +0900
Subject: [PATCH 19/22] docs: remove duplicated if

---
 system/Database/Forge.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/system/Database/Forge.php b/system/Database/Forge.php
index bf19980240ef..85135388c0f7 100644
--- a/system/Database/Forge.php
+++ b/system/Database/Forge.php
@@ -465,7 +465,7 @@ public function dropKey(string $table, string $keyName, bool $prefixKeyName = tr
     }
 
     /**
-     * Checks if if key needs to be dropped as a constraint.
+     * Checks if key needs to be dropped as a constraint.
      */
     protected function dropKeyAsConstraint(string $table, string $constraintName): bool
     {

From ee1076639abb24d190a9181daf6fa97f47b237ac Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 20:32:00 +0900
Subject: [PATCH 20/22] refactor: replace `! is_array()` with `is_string()`

---
 system/Database/Forge.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/system/Database/Forge.php b/system/Database/Forge.php
index 85135388c0f7..79bf94e2c9f7 100644
--- a/system/Database/Forge.php
+++ b/system/Database/Forge.php
@@ -734,7 +734,7 @@ public function renameTable(string $tableName, string $newTableName)
     public function addColumn(string $table, $fields): bool
     {
         // Work-around for literal column definitions
-        if (! is_array($field)) {
+        if (is_string($fields)) {
             $fields = [$fields];
         }
 
@@ -792,7 +792,7 @@ public function dropColumn(string $table, $columnNames)
     public function modifyColumn(string $table, $fields): bool
     {
         // Work-around for literal column definitions
-        if (! is_array($field)) {
+        if (is_string($fields)) {
             $fields = [$fields];
         }
 

From 04b66435e7ad5222089c10b7bee786a2086aaf3e Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 19 Jan 2024 20:40:32 +0900
Subject: [PATCH 21/22] docs: fix @return types

---
 system/Database/Forge.php | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/system/Database/Forge.php b/system/Database/Forge.php
index 79bf94e2c9f7..adbdc208fc47 100644
--- a/system/Database/Forge.php
+++ b/system/Database/Forge.php
@@ -501,7 +501,7 @@ public function dropPrimaryKey(string $table, string $keyName = ''): bool
     }
 
     /**
-     * @return BaseResult|bool|false|mixed|Query
+     * @return bool
      *
      * @throws DatabaseException
      */
@@ -621,7 +621,7 @@ protected function _createTableAttributes(array $attributes): string
     }
 
     /**
-     * @return mixed
+     * @return bool
      *
      * @throws DatabaseException
      */
@@ -687,7 +687,7 @@ protected function _dropTable(string $table, bool $ifExists, bool $cascade)
     }
 
     /**
-     * @return mixed
+     * @return bool
      *
      * @throws DatabaseException
      */

From 213f0b94047fe58766e7008674c6a7569593a3d9 Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Sat, 20 Jan 2024 09:33:41 +0900
Subject: [PATCH 22/22] refactor: add $columnNamesToDrop

---
 system/Database/SQLSRV/Forge.php  | 12 +++++++-----
 system/Database/SQLite3/Forge.php |  4 +++-
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/system/Database/SQLSRV/Forge.php b/system/Database/SQLSRV/Forge.php
index 08e7952e7a0b..522d5fa02f54 100755
--- a/system/Database/SQLSRV/Forge.php
+++ b/system/Database/SQLSRV/Forge.php
@@ -136,15 +136,17 @@ protected function _alterTable(string $alterType, string $table, $processedField
     {
         // Handle DROP here
         if ($alterType === 'DROP') {
+            $columnNamesToDrop = $processedFields;
+
             // check if fields are part of any indexes
             $indexData = $this->db->getIndexData($table);
 
             foreach ($indexData as $index) {
-                if (is_string($processedFields)) {
-                    $processedFields = explode(',', $processedFields);
+                if (is_string($columnNamesToDrop)) {
+                    $columnNamesToDrop = explode(',', $columnNamesToDrop);
                 }
 
-                $fld = array_intersect($processedFields, $index->fields);
+                $fld = array_intersect($columnNamesToDrop, $index->fields);
 
                 // Drop index if field is part of an index
                 if ($fld !== []) {
@@ -155,7 +157,7 @@ protected function _alterTable(string $alterType, string $table, $processedField
             $fullTable = $this->db->escapeIdentifiers($this->db->schema) . '.' . $this->db->escapeIdentifiers($table);
 
             // Drop default constraints
-            $fields = implode(',', $this->db->escape((array) $processedFields));
+            $fields = implode(',', $this->db->escape((array) $columnNamesToDrop));
 
             $sql = <<<SQL
                 SELECT name
@@ -172,7 +174,7 @@ protected function _alterTable(string $alterType, string $table, $processedField
 
             $sql = 'ALTER TABLE ' . $fullTable . ' DROP ';
 
-            $fields = array_map(static fn ($item) => 'COLUMN [' . trim($item) . ']', (array) $processedFields);
+            $fields = array_map(static fn ($item) => 'COLUMN [' . trim($item) . ']', (array) $columnNamesToDrop);
 
             return $sql . implode(',', $fields);
         }
diff --git a/system/Database/SQLite3/Forge.php b/system/Database/SQLite3/Forge.php
index f9b6b8af23c6..d7112c61389f 100644
--- a/system/Database/SQLite3/Forge.php
+++ b/system/Database/SQLite3/Forge.php
@@ -120,10 +120,12 @@ protected function _alterTable(string $alterType, string $table, $processedField
     {
         switch ($alterType) {
             case 'DROP':
+                $columnNamesToDrop = $processedFields;
+
                 $sqlTable = new Table($this->db, $this);
 
                 $sqlTable->fromTable($table)
-                    ->dropColumn($processedFields)
+                    ->dropColumn($columnNamesToDrop)
                     ->run();
 
                 return ''; // Why empty string?