在添加之前检查条目

Question

I need help, I need a query that will check and will not allow adding a new entry as long as the value in the datanumber column does not repeat, but on the condition that the name is the same in the dataname column. Screen

Scenario: I am adding a new entry [dataname] [datanumber]:

1. SENIOR | 3 - write
2. WEB | 2 - write
3. SENIOR | 2 - unable to write
4. ADMIN | 2 - write
5. ADMIN | 2 - unable to write

Answer 1

Solution below

ALTER TABLE my_table_name 
ADD CONSTRAINT MyUniqueConstraint UNIQUE(dataname, datanumber)