求DB2 delete sql 语句,该怎么处理

求DB2 delete sql 语句
CREATE
  TABLE X
  (
  A VARCHAR(10) NOT NULL,
  B INTEGER NOT NULL,
  CONSTRAINT CC1315882009531 PRIMARY KEY (A, B)
  );

CREATE
  TABLE Y
  (
  A VARCHAR(10) NOT NULL,
  B INTEGER NOT NULL,
  CONSTRAINT CC1315882056921 PRIMARY KEY (A, B)
  );

TABLE X
A B
--------------
10 1
10 2
20 1
20 2
30 1
30 2
30 3
30 4
40 3
40 4

TABLE Y
A B
--------------
10 1
10 2
10 3
10 4
20 1
20 2
20 3
20 4

求一条SQL，将Y表中与X表重复的数据删除，即从Y表删除下列查询结果的数据：
SELECT x.a,x.b FROM x,y where x.a=y.a and x.b=y.b
10 1
10 2
20 1
20 2



------解决方案--------------------------------------------------------

SQL code

delete from Y where exists (  select * from X where X.A = Y.A and X.B = Y.B)
------解决方案--------------------------------------------------------
试试
delete from  
(select y.* from y left join x on  X.A = Y.A and X.B = Y.B where x.a is not null) t