We can use ‘COMMENT’ keyword with ALTER TABLE command while modifying the column to add comments on columns. For example if we want to add comment in column ‘id’ of table ‘testing’ then following query will do it −
mysql> ALTER TABLE testing MODIFY id INT COMMENT 'id of employees'; Query OK, 0 rows affected (0.07 sec) Records: 0 Duplicates: 0 Warnings: 0
With following query it can be checked in the comment field of a column.
mysql> Show full columns from testing\G *************************** 1. row *************************** Field: id Type: int(11) Collation: NULL Null: NO Key: PRI Default: 0 Extra: Privileges: select,insert,update,references Comment: id of employees *************************** 2. row *************************** Field: Name Type: varchar(20) Collation: latin1_swedish_ci Null: YES Key: Default: NULL Extra: Privileges: select,insert,update,references Comment: 2 rows in set (0.05 sec)