【DB2】经典SQL写法

CREATE TABLE DataInfo(
ID_1 VARCHAR(10),
ID_2 VARCHAR(10)
)


INSERT INTO DataInfo VALUES(‘A‘,‘Oracle‘);
INSERT INTO DataInfo VALUES(‘B‘,‘sqlserver‘);
INSERT INTO DataInfo VALUES(‘C‘,‘DB2‘);
INSERT INTO DataInfo VALUES(‘DB2‘,‘C‘);
INSERT INTO DataInfo VALUES(‘Oracle‘,‘A‘);
INSERT INTO DataInfo VALUES(‘sqlserver‘,‘B‘);

--删除重复数据

DELETE FROM DataInfo A WHERE EXISTS (SELECT 1 FROM DataInfo B WHERE A.ID_1=B.ID_2 AND A.ID_2=B.ID_1)
AND A.ID_1>A.ID_2
ORDER BY ID_2