mysqltest case virtual_column_sqlqa.generate_ddl_stored_mysql fails with error 1210 on ALTER TABLE ADD INT ... AS('') STORED in SeekDB

[chyujing]

Description

The mysqltest case virtual_column_sqlqa.generate_ddl_stored_mysql fails when executing the statement ALTER TABLE ADD INT generated_column AS('') STORED in SeekDB, resulting in error 1210.

Steps to Reproduce

1. Log into the machine.
2. Navigate to the directory /obdata/data/AndroidTest/ob_opensource_test/tools/deploy.
3. Execute the relevant test.

Impact

This bug causes a specific mysqltest case to fail, indicating an issue with parsing or executing ALTER TABLE statements that add a generated column with an empty string expression (AS('')) in SeekDB mode.