I created a table in PostgreSQL like this:
CREATE TABLE Table1 (
Id varchar(100) PRIMARY KEY CHECK (Id ~ '^[a-z0-9]{3,15}$'),
...
);
This will automatically create a constraint called table1_id_check.
Now I would like to change the check constraint to
(Id ~ '^[a-z0-9]{3,}$')
How can I do this in PostgreSQL as a single statement without dropping the constraint and recreating it again?
Using multiple statements within a transaction works on all SQL dbms that support using this DDL in a transaction.
begin transaction;
alter table table1
drop constraint table1_id_check;
alter table table1
add constraint table1_id_check CHECK (Id ~ '^[a-z0-9]{3,}$');
commit;
PostgreSQL lets you use multiple clauses within an ALTER TABLE statement.
alter table table1
drop constraint table1_id_check,
add constraint table1_id_check CHECK (Id ~ '^[a-z0-9]{3,}$');
