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That is part of SSDT but a step that runs before the dacfx publish. We use premodel scripts in our deplyment pipeline. Martin Smith mentioned this option in a comment, and it's the solution that This column, the main part of the script will fail (because it assumes theĬolumn doesn't exist, based on the results of the schema compare in step #1) Solution: pre-SSDT script When a new column exists in the dacpac and not in the target database, step #2
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#Sql server alter table add column update
The approach I have heard from others is to directly update the table definition (so the schema refresh is consistent), write a predeployment script that moves the entire contents of the table to a temporary table with the new column population logic included, then to move the rows back in a postdeployment script. Adding the column as nullable now with the intention of changing to NOT NULL in the future does not work across multiple branches/forks in source control, as the target systems will not necessarily all have the table in the same state next time they are upgraded (not that this is a good approach anyway IMO).Altering the column to NOT NULL in a post-deployment script will be reverted each time the SSDT schema refresh occurs (so at the very least our codebase will mismatch between source control and what is actually on the server).Adding the column in a pre-deployment script will fail the publish when it automatically tries to create the same column, a second time (even if the pre-deployment script is written to be idempotent) (this one is really aggravating as I can otherwise think of an easy solution).Perhaps it is a foreign key column, but for others we cannot use a fake value like 0 or -1 because those values might have significance (e.g. A default value is not appropriate, and it cannot be a computed column.I have been banging my head against the wall for a while over this simple-sounding task due to some realizations:
#Sql server alter table add column how to
Unlike previous questions that explain how to do this manually, this needs to be managed by the SSDT publish. Therefore it should be added to the table as NOT NULL. Due to business logic, we need a new column in a table that is critical to ensure is always populated.