我有一个表,其中字符串1和2几乎是重复的-它们具有相同的值,但顺序相反。如何删除这些重复项?
+--------+-------+
| COL_1 | COL_@ |
+--------+-------+
| a1 | b1 |
| b1 | a1 | <- same as 1stline but in reversed order,needs to be removed
| a2 | b2 |
| a3 | b3 |
| b3 | a3 |<-- also is duplicate of string above,one of these 2str need
+--------+-------+ to be removed
expected result:
+--------+-------+
| COL_1 | COL_@ |
+--------+-------+
| b1 | a1 |
| a2 | b2 |
| a3 | b3 |
+--------+-------+
or
+--------+-------+
| COL_1 | COL_@ |
+--------+-------+
| a1 | b1 |
| a2 | b2 |
| a3 | b3 |
+--------+-------+