how to check whether on delete property is set or not in a foreign key constraint in postgresql?

Question

Is there is any query to check whether "on delete" property is being set or not set in a foreign key constraint in postgresql ?

Answer 1

You can query the INFORMATION_SCHEMA:

SELECT  UPDATE_RULE, DELETE_RULE
FROM    INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS
WHERE   CONSTRAINT_NAME = 'FK_YourForeignKey';

Example on SQL Fiddle

Answer 2

The pg_constraint table in the system catalog contains this information. You can query that:

select confdeltype from pg_constraint where conrelid=xx and contype='f' and conname='xxxx';

The where clauses here are an example - tweak them to suit.

For a portable solution, query information_schema.table_constraints.