032.PGSQL-pgsql的except-除了， intersect-交集

except 可以查看表一中不在表二的数据；

intersect 可以查看表一和表二一样的数据，求交集；

SELECT rid FROM "o_ls_test" except SELECT rid FROM "o_ls_test_1" 

SELECT rid FROM "o_ls_test" intersect  SELECT rid FROM "o_ls_test_1"