Not Letting the user input a value that already exists..

[PatrickB101]

Not Letting the user input a value that already exists..

I am not sure I have done sever vb programs nothing to do with database programs.. So bear with me. I understand i need to do this in a when validate item trigger.
do you know what the syntax for if item equals a item that already exist in the database then ... so on and so forth ?

regards,
Patrick

 

[stefanhei]

Hi.
Best way is to create a unique constraint on the column you want to be unique:
ALTER TABLE yourTable ADD CONSTRAINT key_name UNIQUE KEY (yourColumn)

Also works for a set of columns.

Stefan