Question

我当前的查询：

select IFNULL(max(rank),0) from (SELECT  date,if(field1 != '1',@rownum := ifnull(@rownum,0)+ 1,@rownum := ifnull(@rank,0))AS rank FROM callinfo as t where t.date > CONVERT_TZ(NOW(), @@session.time_zone, '+0:00') + INTERVAL -600 SECOND  AND t.date <= CONVERT_TZ(NOW(), @@session.time_zone, '+0:00') AND user_id = 16 order by date) as x;

以上查询有子查询：

SELECT  date,if(field1 != '1',@rownum := ifnull(@rownum,0)+ 1,@rownum := ifnull(@rank,0))AS rank FROM callinfo as t where t.date > CONVERT_TZ(NOW(), @@session.time_zone, '+0:00') + INTERVAL -600 SECOND  AND t.date <= CONVERT_TZ(NOW(), @@session.time_zone, '+0:00') AND user_id = 16 order by date

在第一次运行中给出输出：

+-----------------------------+------+
| date                        | rank |
+-----------------------------+------+
| 2018-06-18 09:21:34.1529314 | 1    |
| 2018-06-18 09:21:34.1529314 | 2    |
| 2018-06-18 09:21:54.1529314 | 0    |
| 2018-06-18 09:22:27.1529314 | 0    |
| 2018-06-18 09:04:21.1529313 | 1    |
| 2018-06-18 09:04:21.1529313 | 2    |
| 2018-06-18 09:23:29.1529314 | 0    |
| 2018-06-18 09:21:37.1529314 | 1    |
| 2018-06-18 09:21:37.1529314 | 2    |
+-----------------------------+------+
9 rows in set (0.00 sec)

第二轮：

+-----------------------------+------+
| date                        | rank |
+-----------------------------+------+
| 2018-06-18 09:21:34.1529314 | 3    |
| 2018-06-18 09:21:34.1529314 | 4    |
| 2018-06-18 09:21:54.1529314 | 0    |
| 2018-06-18 09:22:27.1529314 | 0    |
| 2018-06-18 09:04:21.1529313 | 1    |
| 2018-06-18 09:04:21.1529313 | 2    |
| 2018-06-18 09:23:29.1529314 | 0    |
| 2018-06-18 09:21:37.1529314 | 1    |
| 2018-06-18 09:21:37.1529314 | 2    |
+-----------------------------+------+
9 rows in set (0.00 sec)

问题：

在这里我们可以看到第一次运行的子查询提供了1,2结果，而在第二次运行中，它给前两行提供了3,4。所以两种情况都应该相同。
这里我试图从查询中获得最大排名，因此输出应该是排名列中的最大值。

但在这两种情况下，它都没有按预期工作。有人喜欢帮忙吗？

使用选择查询增加变量值

0 个答案: