Useful MySQL Commands

Useful MySql Commands

ALTER TABLE master_activity_log CHANGE `from_user_id` `user_id` INT(11); // change column name
ALTER TABLE master_activity_log DROP log_date; // remove column
ALTER TABLE master_activity_log ADD COLUMN log_datetime DATETIME AFTER after_save; // create new column of existing table

Truncate foreign key constraints table :

SET FOREIGN_KEY_CHECKS = 0; 
TRUNCATE TABLE `table name`;
SET FOREIGN_KEY_CHECKS=1;

// to change the table colum datatype
ALTER TABLE tablename MODIFY columnname VARCHAR(20) ;