Getting Primary Key Constraints in PostgreSQL

select tc.table_schema, tc.table_name, kc.column_name   from        information_schema.table_constraints tc,        information_schema.key_column_usage kc    where       tc.constraint_type = 'PRIMARY KEY'       and kc.table_name = tc.table_name and kc.table_schema = tc.table_schema      and kc.constraint_name = tc.constraint_name  order by 1, 2;

​ 

"We can't solve problems by using the same kind of thinking we used when we created them - Albert Einstein"