Adding Foreign key constraint without checking existing data in Postgres

Question

ALTER TABLE <table name> WITH NOCHECK
    ADD CONSTRAINT attachments_user_id_fkey FOREIGN KEY (user_id)
    REFERENCES public.users (id) MATCH SIMPLE
    ON UPDATE NO ACTION
    ON DELETE NO ACTION;

The above query is throwing the following error ERROR: syntax error at or near "WITH NOCHECK"

Answer 1

That appears to be SQL Server syntax. PostgreSQL doesn't support that WITH NOCHECK, I think you want:

ALTER TABLE <table name>
ADD CONSTRAINT attachments_user_id_fkey FOREIGN KEY (user_id)
REFERENCES public.users (id) NOT VALID

You'll have to check the documentation to see if there are equivalents for the rest of the options you're trying to use.