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We have a two tables with a one-to-many relationship. We would like to enforce a constraint that at least one child record exist for a given parent record.
Is this possible?
If not, would you change the schema a bit more complex to support such a constraint? If so how would you do it?
Edit: I’m using SQL Server 2005
Such a constraint isn’t possible from a schema perspective, because you run into a ‘chicken or the egg’ type of scenario. Under this sort of scenario, when I insert into the parent table I have to have a row in the child table, but I can’t have a row in the child table until there’s a row in the parent table.
This is something better enforced client-side.