unique by 2 columns

[9three]

Hi,

 

I'm wondering if its possible to have 2 columns and have the data in them (integers) be unique to each other.

 

Example:

 

Column 1 - Column 2

 

1000 - 4522

 

Never again can that combination exist or 4522 - 1000 exist unless the row is deleted.

 

Is this possible?

[premiso]

Sure, the way you would do it would be in the code and not in the DB.

 

A simple query to check:

 

SELECT id FROM table WHERE col1 = someint AND col2 = someint;

 

If it exists then you do not insert it and re-generate a number, granted the more columns you have the potentially longer this process could take.

[9three]

Yea I already have something simliar to that I just thought there might be something like a UNIQUE Constraint but for two columns.

 

thanks anyway

[premiso]

I do not know of any double unique constraints that would work in the way you describe. It will most likely have to be done on the code side (unless I am mistaken which I doubt I am).