Question

我有一张这样的桌子：

CREATE TABLE IF NOT EXISTS `exam_results` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `student_code` int(11) NOT NULL,
  `total_level` int(11) NOT NULL,
  `total_rank` int(11) NOT NULL,
  `total_level_2` int(11) NOT NULL,
  `total_rank_2` int(11) NOT NULL,
);

total_level 且 total_rank 且 total_level_2 包含值但 total_rank_2 为空

我想选择 total_level_2 的值，并在 total_level 中找到最接近的值，然后使用找到的行的 total_rank 更新 total_rank_2

如何在查询中执行此操作？

更新

total_level    |    total_rank    |    total_level_2    |    total_rank_2
--------------------------------------------------------------------------
1500           |    100           |    2000             |    ?
--------------------------------------------------------------------------
1700           |    90            |    3500             |    ?
--------------------------------------------------------------------------
2000           |    70            |    1500             |    ?

例如，更新后的最后一行应为100。因为最后一行中 total_level_2 的最接近值在第一行内，所以最后一行的 total_rank_2 将是第一行的 total_rank

更新后的表格：

total_level    |    total_rank    |    total_level_2    |    total_rank_2
--------------------------------------------------------------------------
1500           |    100           |    2000             |    70
--------------------------------------------------------------------------
1700           |    90            |    3500             |    70
--------------------------------------------------------------------------
2000           |    70            |    1500             |    100

Answer 1

试试这个：

clientCertificateMappingAuthentication

Answer 2

CREATE TEMPORARY TABLE IF NOT EXISTS tempresults_cal AS (select cni.*,
                       (select   total_rank
                        from     exam_results ci
                        where ci.analyze_id="'.$Params->get('analyze_id').'"
                        order by abs(total_level - cni.total_level_2)
                        limit 1
                       ) as new_rank
                from exam_results cni;

                UPDATE exam_results
                INNER
                  JOIN tempresults_cal
                    ON tempresults_cal.id = exam_results.id 
                   SET exam_results.total_rank_2 = tempresults_cal.new_rank

mysql根据其他列的最近值更新列

2 个答案: