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mysql指定ID排序,MySQL 按指定字段自定义列表排序,MySql查询结果排序
mysql指定ID排序,MySQL 按指定字段自定义列表排序,MySql查询结果排序
方法一、
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select * from table1 order by instr('1,4,5,7,2',id)
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方法二、
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select * from test where id in(3,1,5) order by find_in_set(id,'3,1,5');
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方法三、
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select * from test where id in(3,1,5) order by substring_index('3,1,2',id,1);
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方法四、
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select * from a where id in(8,11,3) order by field(id,8,11,3);
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大家都知道, MySQL 中按某字段升序排列的 SQL 为 (以 id 为例, 下同):
SELECT * FROM `MyTable`
WHERE `id` IN (1, 7, 3, 5)
ORDER BY `id` ASC
降序排列的 SQL 为:
SELECT * FROM `MyTable`
WHERE `id` IN (1, 7, 3, 5)
ORDER BY `id` DESC
有时以上排序并不能满足我们的需求. 例如, 我们想要按 id 以 5, 3, 7, 1 的顺序排列, 该如何实现. 这也是很多国内外同行经常遇到的问题之一.
下面我们给出按表中某字段, 以我们想要的列表方式排序的解决方案.
解决方案
用"按字段排序" (ORDER BY FIELD).
语法ORDER BY FIELD(`id`, 5, 3, 7, 1)
要注意的是, FIELD 后面是没有空格的.
因此, 完整的 SQL 为:
SELECT * FROM `MyTable`
WHERE `id` IN (1, 7, 3, 5)
ORDER BY FIELD(`id`, 5, 3, 7, 1)
常见应用
SELECT * FROM `MyTable`
WHERE `name` IN ('张三', '李四', '王五', '孙六')
ORDER BY FIELD(`name`, '李四', '孙六', '张三', '王五')
参考资料
Handy MySQL - ORDER BY FIELD
Sort results by order in list
===============================华丽的分隔符=========================================
个人总结，有三种方法实现
mysql> select * from a;
+------+------+
| a | b |
+------+------+
| 4 | 5 |
| 3 | 5 |
| -11 | 1 |
| 8 | 3 |
| 1 | 0 |
+------+------+
5 rows in set (0.00 sec)
mysql> select * from a where a in(8,-11,3) order by field(a,8,-11,3);
+------+------+
| a | b |
+------+------+
| 8 | 3 |
| -11 | 1 |
| 3 | 5 |
+------+------+
3 rows in set (0.00 sec)
mysql> select * from a where a in(8,-11,3) order by find_in_set(a,'8,-11,3');
+------+------+
| a | b |
+------+------+
| 8 | 3 |
| -11 | 1 |
| 3 | 5 |
+------+------+
3 rows in set (0.00 sec)
mysql> select * from a where a in(8,-11,3) order by substring_index('8,-11,3',a,1);
+------+------+
| a | b |
+------+------+
| 8 | 3 |
| -11 | 1 |
| 3 | 5 |
+------+------+
3 rows in set (0.00 sec)
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