add support for nested path columns in JSON_TABLE

Author: lovasoa

src/parser/mod.rs

@@ -10401,6 +10401,18 @@ impl<'a> Parser<'a> {
     /// Parses MySQL's JSON_TABLE column definition.
     /// For example: `id INT EXISTS PATH '$' DEFAULT '0' ON EMPTY ERROR ON ERROR`
     pub fn parse_json_table_column_def(&mut self) -> Result<JsonTableColumn, ParserError> {
+        if self.parse_keyword(Keyword::NESTED) {
+            let _has_path_keyword = self.parse_keyword(Keyword::PATH);
+            let path = self.parse_value()?;
+            self.expect_keyword(Keyword::COLUMNS)?;
+            let columns = self.parse_parenthesized(|p| {
+                p.parse_comma_separated(Self::parse_json_table_column_def)
+            })?;
+            return Ok(JsonTableColumn::Nested(JsonTableNestedColumn {
+                path,
+                columns,
+            }));
+        }
         let name = self.parse_identifier(false)?;
         if self.parse_keyword(Keyword::FOR) {
             self.expect_keyword(Keyword::ORDINALITY)?;

tests/sqlparser_mysql.rs

@@ -2761,6 +2761,9 @@ fn parse_json_table() {
     mysql().verified_only_select(
         r#"SELECT jt.* FROM JSON_TABLE('["Alice", "Bob", "Charlie"]', '$[*]' COLUMNS(row_num FOR ORDINALITY, name VARCHAR(50) PATH '$')) AS jt"#,
     );
+    mysql().verified_only_select(
+        r#"SELECT * FROM JSON_TABLE('[ {"a": 1, "b": [11,111]}, {"a": 2, "b": [22,222]}, {"a":3}]', '$[*]' COLUMNS(a INT PATH '$.a', NESTED PATH '$.b[*]' COLUMNS (b INT PATH '$'))) AS jt"#,
+    );
     assert_eq!(
         mysql()
             .verified_only_select(