DESC table_with_generated_column;
SHOW CREATE TABLE table_with_generated_column;
If generated expression in DDL references bad column, throw error;
If alter table change/drop column dependent by other columns, throw error;
if alter table change/modify generated columns, throw error if needs.
* *: add leak test and tiny clean up
* *: unify test format and add leak test
Conflicts:
store/localstore/compactor_test.go
mysql/error_test.go
*: add leak test
