Add support for MYSQL's CREATE TABLE SELECT expr (apache#1515)

Author: wugeer

src/dialect/mod.rs

@@ -633,6 +633,11 @@ pub trait Dialect: Debug + Any {
     fn supports_comment_on(&self) -> bool {
         false
     }
+
+    /// Returns true if the dialect supports the `CREATE TABLE SELECT` statement
+    fn supports_create_table_select(&self) -> bool {
+        false
+    }
 }
 
 /// This represents the operators for which precedence must be defined

src/dialect/mysql.rs

@@ -97,6 +97,11 @@ impl Dialect for MySqlDialect {
     fn supports_limit_comma(&self) -> bool {
         true
     }
+
+    /// see <https://dev.mysql.com/doc/refman/8.4/en/create-table-select.html>
+    fn supports_create_table_select(&self) -> bool {
+        true
+    }
 }
 
 /// `LOCK TABLES`

src/parser/mod.rs

@@ -5990,6 +5990,11 @@ impl<'a> Parser<'a> {
         // Parse optional `AS ( query )`
         let query = if self.parse_keyword(Keyword::AS) {
             Some(self.parse_query()?)
+        } else if self.dialect.supports_create_table_select() && self.parse_keyword(Keyword::SELECT)
+        {
+            // rewind the SELECT keyword
+            self.prev_token();
+            Some(self.parse_query()?)
         } else {
             None
         };

tests/sqlparser_common.rs

@@ -6501,7 +6501,17 @@ fn parse_multiple_statements() {
     );
     test_with("DELETE FROM foo", "SELECT", " bar");
     test_with("INSERT INTO foo VALUES (1)", "SELECT", " bar");
-    test_with("CREATE TABLE foo (baz INT)", "SELECT", " bar");
+    // Since MySQL supports the `CREATE TABLE SELECT` syntax, this needs to be handled separately
+    let res = parse_sql_statements("CREATE TABLE foo (baz INT); SELECT bar");
+    assert_eq!(
+        vec![
+            one_statement_parses_to("CREATE TABLE foo (baz INT)", ""),
+            one_statement_parses_to("SELECT bar", ""),
+        ],
+        res.unwrap()
+    );
+    // Check that extra semicolon at the end is stripped by normalization:
+    one_statement_parses_to("CREATE TABLE foo (baz INT);", "CREATE TABLE foo (baz INT)");
     // Make sure that empty statements do not cause an error:
     let res = parse_sql_statements(";;");
     assert_eq!(0, res.unwrap().len());
@@ -11717,3 +11727,24 @@ fn parse_comments() {
         ParserError::ParserError("Expected: comment object_type, found: UNKNOWN".to_string())
     );
 }
+
+#[test]
+fn parse_create_table_select() {
+    let dialects = all_dialects_where(|d| d.supports_create_table_select());
+    let sql_1 = r#"CREATE TABLE foo (baz INT) SELECT bar"#;
+    let expected = r#"CREATE TABLE foo (baz INT) AS SELECT bar"#;
+    let _ = dialects.one_statement_parses_to(sql_1, expected);
+
+    let sql_2 = r#"CREATE TABLE foo (baz INT, name STRING) SELECT bar, oth_name FROM test.table_a"#;
+    let expected =
+        r#"CREATE TABLE foo (baz INT, name STRING) AS SELECT bar, oth_name FROM test.table_a"#;
+    let _ = dialects.one_statement_parses_to(sql_2, expected);
+
+    let dialects = all_dialects_where(|d| !d.supports_create_table_select());
+    for sql in [sql_1, sql_2] {
+        assert_eq!(
+            dialects.parse_sql_statements(sql).unwrap_err(),
+            ParserError::ParserError("Expected: end of statement, found: SELECT".to_string())
+        );
+    }
+}