mysql积累

INSERT INTO t_ent_service(ent_id,service_id) SELECT * FROM (SELECT '1','2') AS tmp

WHERE NOT EXISTS

(SELECT 1 FROM t_ent_service WHERE ent_id ='1' AND service_id='2')

AND

(SELECT 1 FROM t_ent WHERE ent_id = '1243434312')

AND

(SELECT 1 FROM t_service WHERE service_id = '2325235235235256')

 INSERT INTO t_ent_service(ent_id,service_id,service_status,licence_num,service_exp_time,service_start_time,customized_patams) 
SELECT '1','2',1,20,'123',SYSDATE(),'备注信息' FROM DUAL
WHERE NOT EXISTS
(SELECT 1 FROM t_ent_service WHERE ent_id ='1' AND service_id='2')
AND
(SELECT 1 FROM t_ent WHERE ent_id = '1243434312')
AND
(SELECT 1 FROM t_service WHERE service_id = '2325235235235256') 

http://stackoverflow.com/questions/3164505/mysql-insert-record-if-not-exists-in-table