Feat(mysql): support ALTER TABLE ... RENAME INDEX. (#7511)

* Feat(mysql): support `ALTER TABLE ... RENAME INDEX`.

MySQL 5.7 introduced `ALTER TABLE ... RENAME INDEX old TO new` (and the
`RENAME KEY` synonym) as a metadata-only operation that renames an index
without rebuilding it.

* Update tests/dialects/test_mysql.py

---------

Co-authored-by: Vaggelis Danias <daniasevangelos@gmail.com>

Author: 2 people

sqlglot/expressions/ddl.py

@@ -279,6 +279,10 @@ class AlterRename(Expression):
     pass
 
 
+class RenameIndex(Expression):
+    arg_types = {"this": True, "to": True}
+
+
 class AlterModifySqlSecurity(Expression):
     arg_types = {"expressions": True}
 

sqlglot/generator.py

@@ -5920,3 +5920,8 @@ def altermodifysqlsecurity_sql(self, expression: exp.AlterModifySqlSecurity) ->
     def usingproperty_sql(self, expression: exp.UsingProperty) -> str:
         kind = expression.args.get("kind")
         return f"USING {kind} {self.sql(expression, 'this')}"
+
+    def renameindex_sql(self, expression: exp.RenameIndex) -> str:
+        this = self.sql(expression, "this")
+        to = self.sql(expression, "to")
+        return f"RENAME INDEX {this} TO {to}"

sqlglot/parsers/mysql.py

@@ -301,6 +301,14 @@ class MySQLParser(parser.Parser):
     VALUES_FOLLOWED_BY_PAREN = False
     SUPPORTS_PARTITION_SELECTION = True
 
+    def _parse_alter_table_rename(self):
+        if self._match_texts(("INDEX", "KEY")):
+            old = self._parse_field(any_token=True)
+            self._match_text_seq("TO")
+            new = self._parse_field(any_token=True)
+            return self.expression(exp.RenameIndex(this=old, to=new))
+        return super()._parse_alter_table_rename()
+
     def _parse_generated_as_identity(
         self,
     ) -> (

tests/dialects/test_mysql.py

@@ -196,6 +196,11 @@ def test_ddl(self):
         self.validate_identity("ALTER TABLE t ALTER INDEX i VISIBLE")
         self.validate_identity("ALTER TABLE t ALTER COLUMN c SET INVISIBLE")
         self.validate_identity("ALTER TABLE t ALTER COLUMN c SET VISIBLE")
+        self.validate_identity("ALTER TABLE t RENAME INDEX a TO b")
+        self.validate_identity(
+            "ALTER TABLE t RENAME KEY a TO b",
+            "ALTER TABLE t RENAME INDEX a TO b",
+        )
         self.validate_identity(
             "UPDATE foo JOIN bar ON TRUE SET foo.a = bar.a WHERE foo.id = bar.id"
         )