REMOVE_REPEATS在SphinxQL中不起作用

Question

文档中写着REMOVE_REPEATS ( result_set, column, offset, limit ) - removes repeated adjusted rows with the same 'column' value.，但当我运行select remove_repeats((select * from rt), gid, 0, 10)时，记录gid=22出现了两次，它不是应该只出现一次吗？

mysql> select remove_repeats( (select * from rt),gid,0,10);
+------+------+
| id   | gid  |
+------+------+
|    1 |   11 |
|    2 |   22 |
|    3 |   33 |
|    4 |   22 |
+------+------+
4 rows in set (0.00 sec)

Answer 1

REMOVE_REPEATS()只删除一个接一个的重复行。在您的示例中，如果按gid排序子查询，则可以删除出现的第二个gid=22：

mysql> select remove_repeats( (select * from rt order by gid asc),gid,0,10);
+------+------+
| id   | gid  |
+------+------+
|    1 |   11 |
|    2 |   22 |
|    3 |   33 |
+------+------+
3 rows in set (0.00 sec)