查询两张表主键值不同的记要_Sql Server

查询两张表主键值不同的记录
两张表 t1、t2。t1的主键为a、b列，t2的主键为a1、b1列。（a对应a1，b对应b1）
找出主键相同的记录
select * from t1,t2 where t1.a=t2.c and t1.b=t2.d
找主键值不同的记录应该怎么找呢？（a、b表没有单独的主键，类似id排序之类的）

------解决方案--------------------

SQL code

select * from t1where not exists(select 1  from t2 where t1.a=t2.c and t1.b=t2.d)union all select * from t2where not exists(select 1  from t1 where t1.a=t2.c and t1.b=t2.d)
------解决方案--------------------


SQL codeselect * 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 codeselect * from t1 full join t2 on a=a1 and b=b1where 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 codeSELECT * FROM t1 WHERE EXISTS (SELECT 1 FROM (SELECT a,bFROM t1INTERSECT SELECT a1,b1FROM t2)a WHERE t1.a=A.a AND t1.b=a.B)UNION SELECT * FROM t2 WHERE EXISTS (SELECT 1 FROM (SELECT a,bFROM t1INTERSECT SELECT a1,b1FROM t2)a WHERE t2.a=A.a AND t2.b=a.B)