select * from t1
where not exists(select 1  from t2 where t1.a=t2.c and t1.b=t2.d)
union all 
select * from t2
where not exists(select 1  from t1 where t1.a=t2.c and t1.b=t2.d)

------解决方案--------------------


SQL code
select * from t1,t2 where t1.a=t2.a1 and t1.b=t2.b1

------解决方案--------------------
(select * from t1
EXCEPT  
select * from t1,t2 where t1.a=t2.c and t1.b=t2.d)
union
(select * from t2
EXCEPT  
select * from t1,t2 where t1.a=t2.c and t1.b=t2.d)


------解决方案--------------------
SQL code
select * from t1 full join t2 on a=a1 and b=b1
where a is null or a1 is null

------解决方案--------------------
SQL code

-->找出2个表中不一致的数据
select  * from t1 where id not in 
      (select id from t2)
union 
select * from t2 where id not in
      (select id from t1)

------解决方案--------------------
探讨

SQL code

-->找出2个表中不一致的数据
select  * from t1 where id not in 
      (select id from t2)
union 
select * from t2 where id not in
      (select id from t1)


------解决方案--------------------
SQL code
SELECT * FROM t1 
WHERE EXISTS (SELECT 1 FROM 
(
SELECT a,b
FROM t1
INTERSECT 
SELECT a1,b1
FROM t2)a WHERE t1.a=A.a AND t1.b=a.B)
UNION 
SELECT * FROM t2 
WHERE EXISTS (SELECT 1 FROM 
(
SELECT a,b
FROM t1
INTERSECT 
SELECT a1,b1
FROM t2)a WHERE t2.a=A.a AND t2.b=a.B)