MySQL-এ ON UPDATE CURRENT_TIMESTAMP কলাম থেকে কীভাবে সরাবেন

সিনট্যাক্স

ALTER TABLE yourTableName CHANGE yourTimeStampColumnName yourTimeStampColumnName TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP;

উদাহরণ

টেবিল তৈরি (ON UPDATE CURRENT_TIMESTAMP সহ):

mysql> CREATE TABLE removeOnUpdateCurrentTimeStampDemo (
    -> Id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
    -> Name VARCHAR(20),
    -> UserUpdateTimestamp TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
    -> );

টেবিল বর্ণনা দেখি:

mysql> DESC removeOnUpdateCurrentTimeStampDemo;

+---------------------+-------------+------+-----+-------------------+-----------------------------+
| Field               | Type        | Null | Key | Default           | Extra                       |
+---------------------+-------------+------+-----+-------------------+-----------------------------+
| Id                  | int(11)     | NO   | PRI | NULL              | auto_increment              |
| Name                | varchar(20) | YES  |     | NULL              |                             |
| UserUpdateTimestamp | timestamp   | NO   |     | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
+---------------------+-------------+------+-----+-------------------+-----------------------------+

Extra` কলামে `on update CURRENT_TIMESTAMP` দেখা যাচ্ছে। এখন এটি সরিয়ে ফেলি:

mysql> ALTER TABLE removeOnUpdateCurrentTimeStampDemo
    -> CHANGE UserUpdateTimestamp UserUpdateTimestamp TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP;
Query OK, 0 rows affected (0.16 sec)

mysql> DESC removeOnUpdateCurrentTimeStampDemo;

+---------------------+-------------+------+-----+-------------------+----------------+
| Field               | Type        | Null | Key | Default           | Extra          |
+---------------------+-------------+------+-----+-------------------+----------------+
| Id                  | int(11)     | NO   | PRI | NULL              | auto_increment |
| Name                | varchar(20) | YES  |     | NULL              |                |
| UserUpdateTimestamp | timestamp   | NO   |     | CURRENT_TIMESTAMP |                |
+---------------------+-------------+------+-----+-------------------+----------------+

mysql> ALTER TABLE removeOnUpdateCurrentTimeStampDemo
    -> CHANGE UserUpdateTimestamp UserUpdateTimestamp TIMESTAMP NOT NULL;