SQL: Introduce Coalesce function (#35253)

Add Coalesce conditional for replacing null values

Fix #35060

(cherry picked from commit 75e9a63)

Author: costin

x-pack/plugin/sql/qa/security/src/test/java/org/elasticsearch/xpack/sql/qa/security/RestSqlIT.java

@@ -13,18 +13,18 @@
 import org.elasticsearch.test.rest.ESRestTestCase;
 import org.elasticsearch.xpack.sql.qa.rest.RestSqlTestCase;
 
-import static org.elasticsearch.xpack.core.security.authc.support.UsernamePasswordToken.basicAuthHeaderValue;
-
 import java.net.URISyntaxException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 
+import static org.elasticsearch.xpack.core.security.authc.support.UsernamePasswordToken.basicAuthHeaderValue;
+
 /**
  * Integration test for the rest sql action. The one that speaks json directly to a
  * user rather than to the JDBC driver or CLI.
  */
 public class RestSqlIT extends RestSqlTestCase {
-    static final boolean SSL_ENABLED = Booleans.parseBoolean(System.getProperty("tests.ssl.enabled"));
+    static final boolean SSL_ENABLED = Booleans.parseBoolean(System.getProperty("tests.ssl.enabled"), false);
 
     static Settings securitySettings() {
         String token = basicAuthHeaderValue("test_admin", new SecureString("x-pack-test-password".toCharArray()));

x-pack/plugin/sql/qa/src/main/java/org/elasticsearch/xpack/sql/qa/cli/ShowTestCase.java

@@ -35,6 +35,10 @@ public void testShowFunctions() throws IOException {
         while (aggregateFunction.matcher(line).matches()) {
             line = readLine();
         }
+        Pattern conditionalFunction = Pattern.compile("\\s*[A-Z0-9_~]+\\s*\\|\\s*CONDITIONAL\\s*");
+        while (conditionalFunction.matcher(line).matches()) {
+            line = readLine();
+        }
         Pattern scalarFunction = Pattern.compile("\\s*[A-Z0-9_~]+\\s*\\|\\s*SCALAR\\s*");
         while (scalarFunction.matcher(line).matches()) {
             line = readLine();

x-pack/plugin/sql/qa/src/main/java/org/elasticsearch/xpack/sql/qa/jdbc/CsvSpecTestCase.java

@@ -36,7 +36,7 @@ public static List<Object[]> readScriptSpec() throws Exception {
         tests.addAll(readScriptSpec("/columns.csv-spec", parser));
         tests.addAll(readScriptSpec("/datetime.csv-spec", parser));
         tests.addAll(readScriptSpec("/alias.csv-spec", parser));
-        tests.addAll(readScriptSpec("/nulls.csv-spec", parser));
+        tests.addAll(readScriptSpec("/null.csv-spec", parser));
         tests.addAll(readScriptSpec("/nested.csv-spec", parser));
         tests.addAll(readScriptSpec("/functions.csv-spec", parser));
         tests.addAll(readScriptSpec("/math.csv-spec", parser));

x-pack/plugin/sql/qa/src/main/java/org/elasticsearch/xpack/sql/qa/jdbc/JdbcAssert.java

@@ -118,6 +118,11 @@ public static void assertResultSetMetadata(ResultSet expected, ResultSet actual,
             if (expectedType == Types.FLOAT && expected instanceof CsvResultSet) {
                 expectedType = Types.REAL;
             }
+            // csv doesn't support NULL type so skip type checking
+            if (actualType == Types.NULL && expected instanceof CsvResultSet) {
+                expectedType = Types.NULL;
+            }
+
             // when lenient is used, an int is equivalent to a short, etc...
             assertEquals("Different column type for column [" + expectedName + "] (" + JDBCType.valueOf(expectedType) + " != "
                     + JDBCType.valueOf(actualType) + ")", expectedType, actualType);

x-pack/plugin/sql/qa/src/main/java/org/elasticsearch/xpack/sql/qa/jdbc/SqlSpecTestCase.java

@@ -41,6 +41,7 @@ public static List<Object[]> readScriptSpec() throws Exception {
         tests.addAll(readScriptSpec("/arithmetic.sql-spec", parser));
         tests.addAll(readScriptSpec("/string-functions.sql-spec", parser));
         tests.addAll(readScriptSpec("/case-functions.sql-spec", parser));
+        tests.addAll(readScriptSpec("/null.sql-spec", parser));
         return tests;
     }
 

x-pack/plugin/sql/qa/src/main/resources/command.csv-spec

@@ -19,6 +19,7 @@ SKEWNESS        |AGGREGATE
 STDDEV_POP      |AGGREGATE      
 SUM_OF_SQUARES  |AGGREGATE      
 VAR_POP         |AGGREGATE      
+COALESCE        |CONDITIONAL
 DAY             |SCALAR         
 DAYNAME         |SCALAR         
 DAYOFMONTH      |SCALAR         

x-pack/plugin/sql/qa/src/main/resources/docs.csv-spec

@@ -196,6 +196,7 @@ SKEWNESS        |AGGREGATE
 STDDEV_POP      |AGGREGATE      
 SUM_OF_SQUARES  |AGGREGATE      
 VAR_POP         |AGGREGATE      
+COALESCE        |CONDITIONAL
 DAY             |SCALAR         
 DAYNAME         |SCALAR         
 DAYOFMONTH      |SCALAR         

x-pack/plugin/sql/qa/src/main/resources/null.csv-spec

@@ -0,0 +1,75 @@
+//
+// Null expressions
+//
+
+dateTimeOverNull
+SELECT YEAR(CAST(NULL AS DATE)) d;
+
+d:i
+null
+;
+
+addOfNull
+SELECT CAST(NULL AS INT) + CAST(NULL AS FLOAT) AS n;
+
+n:d
+null
+;
+
+
+divOfCastedNull
+SELECT 5 / CAST(NULL AS FLOAT) + 10 AS n;
+
+n:d
+null
+;
+
+divNoNull
+SELECT 5 / null + 1 AS n;
+
+n:i
+null
+;
+
+coalesceJustWithNull
+SELECT COALESCE(null, null, null) AS c;
+
+c
+null
+;
+
+coalesceFirstNotNull
+SELECT COALESCE(123) AS c;
+
+c
+123
+;
+
+
+coalesceWithFirstNullOfString
+SELECT COALESCE(null, 'first') AS c;
+
+c:s
+first
+;
+
+coalesceWithFirstNullOfNumber
+SELECT COALESCE(null, 123) AS c;
+
+c:i
+123
+;
+
+coalesceMixed
+SELECT COALESCE(null, 123, null, 321) AS c;
+
+c:i
+123
+;
+
+coalesceScalar
+SELECT COALESCE(null, ABS(123) + 1) AS c;
+
+c:i
+124
+;

x-pack/plugin/sql/qa/src/main/resources/null.sql-spec

@@ -0,0 +1,12 @@
+//
+// Null expressions
+//
+
+coalesceField
+SELECT COALESCE(null, ABS(emp_no) + 1) AS c FROM test_emp ORDER BY emp_no LIMIT 5;
+
+coalesceHaving
+SELECT COALESCE(null, ABS(MAX(emp_no)) + 1, 123) AS c FROM test_emp GROUP BY languages HAVING c > 100 ORDER BY languages LIMIT 5;
+
+coalesceWhere
+SELECT COALESCE(null, ABS(emp_no) + 1, 123) AS c FROM test_emp WHERE COALESCE(null, ABS(emp_no) + 1, 123, 321) > 100 ORDER BY emp_no NULLS FIRST LIMIT 5;