在MYSQL中按FIELD排序 [英] Order by FIELD in MYSQL

问题描述

我正在努力解决这个问题.我有这样一张桌子.

I am struggling to resolve this . I have a table like this .

    +-------------+-------+
    | type        | COUNT |
    +-------------+-------+
    | A           |     1 |
    | C           |     5 |
    | B           |     4 |
    +-------------+-------+

我要查询表，结果必须是这样.

I want to query the table and the result must be like this .

+-------------+-------+
| type        | COUNT |
+-------------+-------+
| A           |     1 |
| B           |     5 |
| C           |     9 |
| D           |     0 |
+-------------+-------+

查询:

select type , COUNT from TABLE order by FIELD(type,'A','B','C','D') ; 

如果列type的值为'A，B，C，D'，则它可以正常工作.在某些情况下，某些列的FIELD('A','B','C','D')顺序可能在table中没有值.在这种情况下，我想将其设置为0并构造一个结果.

It works fine if the column type has value for 'A,B,C,D' . In some cases the order by FIELD('A','B','C','D') some columns may not have value in table . In this cases I want to put 0 for it and construct a result .

D在表中不存在.因此，将其设置为"0".

D is not there in table . So put '0' for it .

显示创建表的输出

CREATE TABLE `Summary` (
  `TIMESTAMP` bigint(20) NOT NULL DEFAULT '0',
  `type` varchar(50) NOT NULL DEFAULT '',
  `COUNT` bigint(19) NOT NULL,
  PRIMARY KEY (`TIMESTAMP`,`type`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

推荐答案

如何做到这一点:

select a.col as type,coalesce (`COUNT`,0) as `count`
from 
(select 'A' as col union all
select 'B' as col union all
select 'C' as col union all
select 'D' as col )a
left join Table1 T
on a.col=T.type
order by FIELD(a.col,'A','B','C','D') ; 

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