有2个表a和b,2表通过custid和orderno关联
表a
custid orderno contractno
A001 X001 C001
A002 X002 C002
A002 X003 C003
A004 X004 C004表b
custid orderno custname custadress custtel
A001 X001 aaa 121 123456
A002 X002 bbb 122 432133
A002 X003 bbb 122 432133
A004 X004 ddd 123 531235我要的结果是这样的,加入表b有500条记录,那么两表连接后一共显示500条(表b全部显示),如果在表a能找到对应的contractno,则显示contractno,否则空着
custid orderno custname custadress custtel contractno
A001 X001 aaa 121 123456 C001
A002 X002 bbb 122 432133 C002
A002 X003 bbb 122 432133 C003
A004 X004 ddd 123 531235 C004请问这样的sql该如何写?谢谢.
表a
custid orderno contractno
A001 X001 C001
A002 X002 C002
A002 X003 C003
A004 X004 C004表b
custid orderno custname custadress custtel
A001 X001 aaa 121 123456
A002 X002 bbb 122 432133
A002 X003 bbb 122 432133
A004 X004 ddd 123 531235我要的结果是这样的,加入表b有500条记录,那么两表连接后一共显示500条(表b全部显示),如果在表a能找到对应的contractno,则显示contractno,否则空着
custid orderno custname custadress custtel contractno
A001 X001 aaa 121 123456 C001
A002 X002 bbb 122 432133 C002
A002 X003 bbb 122 432133 C003
A004 X004 ddd 123 531235 C004请问这样的sql该如何写?谢谢.
FROM B , A
WHERE B.CUSTID = A.CUSTID(+)
AND B.ORDERNO = A.ORDERNO(+)