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SQL check constraint

Juhan Voolaid
Ranch Hand

Joined: Nov 18, 2003
Posts: 179

It is only about SQL (DDL) and to be more specific - about PostgreSQL.

I have to create a table coordinates with rows: x integer, y integer, id integer, data_set integer. And I allso must specify that in one data_set, there is no dublicated set of coordinates.

My first attempt was like that:

But this one fails, because it does not care about data_set_ID.

So if there is any SQL guru out there, help is very welcome. How would you complete this, or what would you add to the code above?

[ June 11, 2006: Message edited by: Juhan Voolaid ]
Juhan Voolaid
Ranch Hand

Joined: Nov 18, 2003
Posts: 179
Daaaahhhh ...

The solution is more simple than I could excpect in my wildest dreams:

UNIQUE (x, y, data_set_id)
Jeanne Boyarsky
author & internet detective

Joined: May 26, 2003
Posts: 31769

Thanks for posting the solution for others who see this thread in the future.

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subject: SQL check constraint