Add parse_value_table_mode, mvoe tests, update docs

Author: bombsimon

src/ast/query.rs

@@ -3338,11 +3338,8 @@ impl fmt::Display for OpenJsonTableColumn {
 }
 
 /// BigQuery supports ValueTables which have 2 modes:
-/// `SELECT AS STRUCT`
-/// `SELECT AS VALUE`
-///
-/// They can be combined with `[ { ALL | DISTINCT } ]`, e.g.
-/// `SELECT DISTINCT AS STRUCT`
+/// `SELECT [ALL | DISTINCT] AS STRUCT`
+/// `SELECT [ALL | DISTINCT] AS VALUE`
 ///
 /// <https://cloud.google.com/bigquery/docs/reference/standard-sql/query-syntax#value_tables>
 /// <https://cloud.google.com/bigquery/docs/reference/standard-sql/query-syntax#select_list>

src/parser/mod.rs

@@ -11505,31 +11505,7 @@ impl<'a> Parser<'a> {
         }
 
         let select_token = self.expect_keyword(Keyword::SELECT)?;
-        let value_table_mode = if dialect_of!(self is BigQueryDialect) {
-            if self.parse_keywords(&[Keyword::DISTINCT, Keyword::AS]) {
-                if self.parse_keyword(Keyword::VALUE) {
-                    Some(ValueTableMode::DistinctAsValue)
-                } else if self.parse_keyword(Keyword::STRUCT) {
-                    Some(ValueTableMode::DistinctAsStruct)
-                } else {
-                    self.expected("VALUE or STRUCT", self.peek_token())?
-                }
-            } else if self.parse_keyword(Keyword::AS)
-                || self.parse_keywords(&[Keyword::ALL, Keyword::AS])
-            {
-                if self.parse_keyword(Keyword::VALUE) {
-                    Some(ValueTableMode::AsValue)
-                } else if self.parse_keyword(Keyword::STRUCT) {
-                    Some(ValueTableMode::AsStruct)
-                } else {
-                    self.expected("VALUE or STRUCT", self.peek_token())?
-                }
-            } else {
-                None
-            }
-        } else {
-            None
-        };
+        let value_table_mode = self.parse_value_table_mode()?;
 
         let mut top_before_distinct = false;
         let mut top = None;
@@ -11705,6 +11681,32 @@ impl<'a> Parser<'a> {
         })
     }
 
+    fn parse_value_table_mode(&mut self) -> Result<Option<ValueTableMode>, ParserError> {
+        if !dialect_of!(self is BigQueryDialect) {
+            return Ok(None);
+        }
+
+        let mode = if self.parse_keywords(&[Keyword::DISTINCT, Keyword::AS, Keyword::VALUE]) {
+            Some(ValueTableMode::DistinctAsValue)
+        } else if self.parse_keywords(&[Keyword::DISTINCT, Keyword::AS, Keyword::STRUCT]) {
+            Some(ValueTableMode::DistinctAsStruct)
+        } else if self.parse_keywords(&[Keyword::AS, Keyword::VALUE])
+            || self.parse_keywords(&[Keyword::ALL, Keyword::AS, Keyword::VALUE])
+        {
+            Some(ValueTableMode::AsValue)
+        } else if self.parse_keywords(&[Keyword::AS, Keyword::STRUCT])
+            || self.parse_keywords(&[Keyword::ALL, Keyword::AS, Keyword::STRUCT])
+        {
+            Some(ValueTableMode::AsStruct)
+        } else if self.parse_keyword(Keyword::AS) {
+            self.expected("VALUE or STRUCT", self.peek_token())?
+        } else {
+            None
+        };
+
+        Ok(mode)
+    }
+
     /// Invoke `f` after first setting the parser's `ParserState` to `state`.
     ///
     /// Upon return, restores the parser's state to what it started at.

tests/sqlparser_bigquery.rs

@@ -2313,16 +2313,46 @@ fn bigquery_select_expr_star() {
 
 #[test]
 fn test_select_as_struct() {
-    bigquery().verified_only_select("SELECT * FROM (SELECT AS VALUE STRUCT(123 AS a, false AS b))");
+    for (sql, parse_to) in [
+        (
+            "SELECT * FROM (SELECT AS STRUCT STRUCT(123 AS a, false AS b))",
+            "SELECT * FROM (SELECT AS STRUCT STRUCT(123 AS a, false AS b))",
+        ),
+        (
+            "SELECT * FROM (SELECT DISTINCT AS STRUCT STRUCT(123 AS a, false AS b))",
+            "SELECT * FROM (SELECT DISTINCT AS STRUCT STRUCT(123 AS a, false AS b))",
+        ),
+        (
+            "SELECT * FROM (SELECT ALL AS STRUCT STRUCT(123 AS a, false AS b))",
+            "SELECT * FROM (SELECT AS STRUCT STRUCT(123 AS a, false AS b))",
+        ),
+    ] {
+        bigquery().one_statement_parses_to(sql, parse_to);
+    }
+
     let select = bigquery().verified_only_select("SELECT AS STRUCT 1 AS a, 2 AS b");
     assert_eq!(Some(ValueTableMode::AsStruct), select.value_table_mode);
 }
 
 #[test]
 fn test_select_as_value() {
-    bigquery().verified_only_select(
-        "SELECT * FROM (SELECT AS VALUE STRUCT(5 AS star_rating, false AS up_down_rating))",
-    );
+    for (sql, parse_to) in [
+        (
+            "SELECT * FROM (SELECT AS VALUE STRUCT(5 AS star_rating, false AS up_down_rating))",
+            "SELECT * FROM (SELECT AS VALUE STRUCT(5 AS star_rating, false AS up_down_rating))",
+        ),
+        (
+            "SELECT * FROM (SELECT DISTINCT AS VALUE STRUCT(5 AS star_rating, false AS up_down_rating))",
+            "SELECT * FROM (SELECT DISTINCT AS VALUE STRUCT(5 AS star_rating, false AS up_down_rating))",
+        ),
+        (
+            "SELECT * FROM (SELECT ALL AS VALUE STRUCT(5 AS star_rating, false AS up_down_rating))",
+            "SELECT * FROM (SELECT AS VALUE STRUCT(5 AS star_rating, false AS up_down_rating))",
+        ),
+    ] {
+        bigquery().one_statement_parses_to(sql, parse_to);
+    }
+
     let select = bigquery().verified_only_select("SELECT AS VALUE STRUCT(1 AS a, 2 AS b) AS xyz");
     assert_eq!(Some(ValueTableMode::AsValue), select.value_table_mode);
 }
@@ -2377,27 +2407,3 @@ fn test_any_type() {
 fn test_any_type_dont_break_custom_type() {
     bigquery_and_generic().verified_stmt("CREATE TABLE foo (x ANY)");
 }
-
-#[test]
-fn test_select_distinct_or_all_as_struct_or_value() {
-    for sql in [
-        "SELECT DISTINCT AS STRUCT a, ABS(b) FROM UNNEST(c) AS T",
-        "SELECT DISTINCT AS VALUE a, ABS(b) FROM UNNEST(c) AS T",
-        "SELECT ARRAY(SELECT DISTINCT AS STRUCT a, b, ABS(c) AS c, ABS(d) AS d FROM UNNEST(e) AS T)",
-    ] {
-        bigquery().verified_stmt(sql);
-    }
-
-    for (sql, parse_to) in [
-        (
-            "SELECT ALL AS STRUCT a, ABS(b) FROM UNNEST(c) AS T",
-            "SELECT AS STRUCT a, ABS(b) FROM UNNEST(c) AS T",
-        ),
-        (
-            "SELECT ALL AS VALUE a, ABS(b) FROM UNNEST(c) AS T",
-            "SELECT AS VALUE a, ABS(b) FROM UNNEST(c) AS T",
-        ),
-    ] {
-        bigquery().one_statement_parses_to(sql, parse_to);
-    }
-}