Unique constraint

External Article

Declarative SQL: Using UNIQUE Constraints

  • Article

In SQL, you can express the logic of what you want to accomplish without spelling out the details of how the database should do it. Nowhere is this more powerful than in constraints. SQL is declarative, and Joe Celko demonstrates, in his introduction to Declarative SQL, how you can write portable code that performs well and executes some complex logic, merely by creating unique constraints.

2015-12-29

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Question of the Day

A Quick Restore

While doing some testing of an application, I wanted to reset my environment after doing some testing with this code:

USE DNRTest

BACKUP DATABASE DNRTest TO DISK = 'dnrtest.bak'
GO
/*
Bunch of stuff tested here
*/RESTORE DATABASE DNRTest FROM DISK = 'dnrtest.bak' WITH REPLACE
What happens if this runs, assuming the "bunch of stuff" isn't anything affecting the instance.

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