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Removing and Refilling All Tables in a Database

Phil Factor has a couple T-SQL scripts for us to remove and reload a test database:

Copying a database using a BCP dataset from a DOS script or from PowerShell is fairly quick and trivial, but what if the data is already in another copy of the database on the same instance? Imagine you have a database build that is a copy of an existing database on the same instance and you want to run a ‘destructive’ test on the data, and do it over and over again.

Deleting all the data in a database should, you’d have thought, be trivial. Truncation doesn’t work because it doesn’t like to truncate tables with foreign keys, even if they are disabled. DELETE is safer but you will need to then reset any identity columns. Deleting large tables in one chunk isn’t scalable, so you have to do it in smaller chunks. I like to disable triggers while I do this as well. The only disadvantage comes if you have triggers that are supposed to be disabled because the simple code just re-enables them all.

This is, I think, one of the biggest selling points for containers where the database is built into the container image. You spin up a container based off of an image, perform your destructive testing, and destroy the container afterward. The next time you need to run these tests, spin up a new container. And if you need to change the data, modify the container. This introduces new challenges like how SQL Server on Linux has limitations which don’t exist on Windows, but for supported functionality, it’s a nice solution.

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