how to drop a column if exists in mysql? [duplicate]
IF EXISTS(SELECT * FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = 'db_name' AND TABLE_NAME = 'table_name' AND COLUMN_NAME = 'column_name')BEGIN ALTER TABLE table_name DROP COLUMN column_nameENDOR
IF (SELECT COUNT(*) FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = 'db_name' AND TABLE_NAME = 'table_name' AND COLUMN_NAME = 'column_name'>0)BEGIN ALTER TABLE table_name DROP COLUMN column_nameEND