Question

I have two existing tables (TableA and TableB) and I need to add a new column to TableA that has a foreign key to TableB and has a default value that is not null… and both these constraints need to be named. How can I do this?

Answer 1

Adding both constraints in one statement wasn’t as easy as I thought it would be and there didn’t seem to be many examples out there (at least I wasn’t able to find any very easily), so I thought I’d share how I did it here and maybe someone can suggest a better way?

ALTER TABLE [table name] ADD
    [New Column Name] [Column Type] 
    CONSTRAINT [constraint name] DEFAULT ([default value]) NOT NULL,
    CONSTRAINT [constraint name] FOREIGN KEY ([New Column Name]) 
    REFERENCES [Other Table] ([Foreign ID])

Example:

ALTER TABLE tableA ADD
    myNewColumn BIGINT 
    CONSTRAINT myNamedConstraint_df default (1) NOT NULL,
    CONSTRAINT myNamedConstraint_fk FOREIGN KEY (myNewColumn)
    REFERENCES tableB (tableBPrimaryKeyID)