PHP | 如果存在任何具有相同id overdate的记录，Mysql如何停止插入

Question

Well, I have this attendance system who mark an attendance every day, well what I am looking is for a restriction other than PHP code like a restriction that can restrict users to enter duplicate record over time. For e.g I have already marked my attendance .myself

DATE 22-05-2018 and trackingid = 1

if I try to insert mark attendance one more time it should not insert the statement.

It can be done via php and its a long code and i mean like it is possible but is there any way around with MySQL , through which we can make 2 columns unique if they both already exist just dont let user insert .

Answer 1

Use unique_index on your columns

ALTER TABLE `tablename` ADD UNIQUE `unique_index`(`columnOneName`, `columnTwoName`);