如何计算mysql中逗号分隔字符串中子字符串的出现次数

kqqjbcuj  于 2021-08-21  发布在  Java
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假设我选择了这样的记录

+----+-------------------------------------------------------------------------------------
| id | groupedStatus                                                                      |
+----+-------------------------------------------------------------------------------------
| 1 | received,accepted,discarded,discarded,accepted,discarded,accepted,received,received |
| 2 | accepted,discarded,received,received,received,received,received                     |          
+----+-------------------------------------------------------------------------------------

除了上面的记录,我还想得到groupedstatus字符串中每个子字符串的出现情况,
例如,在第一行中,引用如下:
接收:3接受:3丢弃:3
原始表架构
表1

ID int

表2:

ID
Table1ID
Status enum('received','accepted','discarded')

我使用下面的查询选择上面的记录

select t1.id, group_concat(t2.status) as groupedStatus from Table1 t1 inner join Table2 t2 on t1.id=t2.table1ID group by t1.id
tez616oj

tez616oj1#

您可以通过条件聚合来实现这一点,如下所示:

select 
    t1.id, 
    sum(t2.status = 'received')  as received,
    sum(t2.status = 'accepted')  as accepted,
    sum(t2.status = 'discarded') as discarded,
    group_concat(t2.status) as groupedStatus 
from table1 t1 
inner join table2 t2 on t1.id = t2.table1ID 
group by t1.id

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