十万火急,如何写查询语句.
表结构如下:
mysql> select * from dup_view;
+---------+----------+----------+-----------+
| call_id | s_msisdn | o_msisdn | o_call_id |
+---------+----------+----------+-----------+
| 1 | 123456 | 654321 | 2 |
| 2 | 654321 | 123456 | 1 |
| 3 | 98765 | 567890 | 4 |
| 4 | 567890 | 98765 | 3 |
| 5 | 123456 | 999999 | 0 |
+---------+----------+----------+-----------+
5 rows in set (0.00 sec)
如何写查询语句取出表中没有重复的记录,重复的记录是指call_id和o_call_id相互相等的两条记录。如 1和2, 3和4。期望的查询结果是1,3,5。