postgres
test=# CREATE TABLE test (a text, b text); CREATE TABLE test=# ALTER TABLE test ADD CONSTRAINT a_b_key UNIQUE (a, b); NOTICE: ALTER TABLE / ADD UNIQUE will create implicit index "a_b_key" for table "test" ALTER TABLE test=# Create UNIQUE INDEX a_b_idx ON test (a, b); CREATE INDEX
test=# \d test
Table "public.test"
Column | Type | Modifiers
--------+------+-----------
a | text |
b | text |
Indexes:
"a_b_idx" UNIQUE, btree (a, b)
"a_b_key" UNIQUE, btree (a, b)
test=# SELECT * FROM information_schema.table_constraints WHERE table_name='test';
constraint_catalog | constraint_schema | constraint_name | table_catalog | table_schema | table_name | constraint_type | is_deferrable | initially_deferred
--------------------+-------------------+-----------------+---------------+--------------+------------+-----------------+---------------+--------------------
dpj_test | public | a_b_key | dpj_test | public | test | UNIQUE | NO | NO
(1 row)PostgreSQL: Re: How to checking the existance of constraints for a table?
