如何使用MySQL存储过程对管道分隔字段进行计数和排序？
我需要创建一个存储过程，它将返回管道分隔字段中遇到的每个唯一值的总计数，大致如图2所示。幸运的是，如果这使事情变得更简单，那么这些值将永远是“value1”、“value2”或“value3”。我原本计划输出数据并在PHP中进行排序，方法是分解数据并循环字符串匹配，但有一些特殊情况需要我使用存储过程，而我以前从未使用过存储过程 我解释的数据格式如下所示，“valuelist”字段是一个包含许多值的管道分隔字段。我需要找出给定日期的每个值出现的次数 （下图1）数据库中的数据是什么样子的如何使用MySQL存储过程对管道分隔字段进行计数和排序？,mysql,stored-procedures,Mysql,Stored Procedures,我需要创建一个存储过程，它将返回管道分隔字段中遇到的每个唯一值的总计数，大致如图2所示。幸运的是，如果这使事情变得更简单，那么这些值将永远是“value1”、“value2”或“value3”。我原本计划输出数据并在PHP中进行排序，方法是分解数据并循环字符串匹配，但有一些特殊情况需要我使用存储过程，而我以前从未使用过存储过程 我解释的数据格式如下所示，“valuelist”字段是一个包含许多值的管道分隔字段。我需要找出给定日期的每个值出现的次数 （下图1）数据库中的数据是什么样子的 id, d
id, date, valuelist
1, 2017-01-01, value1|value2|value3
2, 2017-01-01, value1|value2
3, 2017-01-01, value1
从db.table中选择日期、值列表的查询，其中id=1将返回2017-01-01，value1 | value2 | value3
（下图2）所需的计数输出，表示每个值在特定日期出现的次数。例如，使用图1中的数据，如果我们询问2017-01-01，输出应该如下所示
value1: 3
value2: 2
value3: 1
假设您正在将3 | 2 | 1
转换为3
，2
，1
的单独行；MySQL（或几乎任何基于SQL的RDBMS）不适合这种输出
无需进入实际的过程代码，在过程中，您可以：
将值存储在局部变量中
使用更通用的存储函数（在这里很容易找到）来“拆分”分隔符上的字符串
；或者使用“get n-th”函数对字符串进行“循环”以迭代方式拆分
将值存储到临时表中
使用临时表上的SELECT作为过程的结果集
看看这个：
按给定样本数据详细说明：
SELECT date,fval as allValue,count(fval) as ValueCount from
(select date,fval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select 1 as id, '2017-01-01' as date, 'value1|value2|value3' as valuelist union all
select 2, '2017-01-01', 'value1|value2' union all
select 3, '2017-01-01', 'value1') as a)as a) as a
union all
select date,sval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select 1 as id, '2017-01-01' as date, 'value1|value2|value3' as valuelist union all
select 2, '2017-01-01', 'value1|value2' union all
select 3, '2017-01-01', 'value1') as a)as a) as a
UNION all
select date,tval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select 1 as id, '2017-01-01' as date, 'value1|value2|value3' as valuelist union all
select 2, '2017-01-01', 'value1|value2' union all
select 3, '2017-01-01', 'value1') as a)as a) as a) as a
where fval !='' GROUP BY fval,date
SELECT date,fval as allValue,count(fval) as ValueCount from
(select date,fval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select * from yourTable) as a)as a) as a
union all
select date,sval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select * from yourTable as a)as a) as a
UNION all
select date,tval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select * from yourTable) as a)as a) as a) as a
where fval !='' GROUP BY fval,date
2017-01-01 value1 3
2017-01-01 value2 2
2017-01-01 value3 1
最终查询：
SELECT date,fval as allValue,count(fval) as ValueCount from
(select date,fval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select 1 as id, '2017-01-01' as date, 'value1|value2|value3' as valuelist union all
select 2, '2017-01-01', 'value1|value2' union all
select 3, '2017-01-01', 'value1') as a)as a) as a
union all
select date,sval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select 1 as id, '2017-01-01' as date, 'value1|value2|value3' as valuelist union all
select 2, '2017-01-01', 'value1|value2' union all
select 3, '2017-01-01', 'value1') as a)as a) as a
UNION all
select date,tval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select 1 as id, '2017-01-01' as date, 'value1|value2|value3' as valuelist union all
select 2, '2017-01-01', 'value1|value2' union all
select 3, '2017-01-01', 'value1') as a)as a) as a) as a
where fval !='' GROUP BY fval,date
SELECT date,fval as allValue,count(fval) as ValueCount from
(select date,fval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select * from yourTable) as a)as a) as a
union all
select date,sval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select * from yourTable as a)as a) as a
UNION all
select date,tval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select * from yourTable) as a)as a) as a) as a
where fval !='' GROUP BY fval,date
2017-01-01 value1 3
2017-01-01 value2 2
2017-01-01 value3 1
结果：
SELECT date,fval as allValue,count(fval) as ValueCount from
(select date,fval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select 1 as id, '2017-01-01' as date, 'value1|value2|value3' as valuelist union all
select 2, '2017-01-01', 'value1|value2' union all
select 3, '2017-01-01', 'value1') as a)as a) as a
union all
select date,sval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select 1 as id, '2017-01-01' as date, 'value1|value2|value3' as valuelist union all
select 2, '2017-01-01', 'value1|value2' union all
select 3, '2017-01-01', 'value1') as a)as a) as a
UNION all
select date,tval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select 1 as id, '2017-01-01' as date, 'value1|value2|value3' as valuelist union all
select 2, '2017-01-01', 'value1|value2' union all
select 3, '2017-01-01', 'value1') as a)as a) as a) as a
where fval !='' GROUP BY fval,date
SELECT date,fval as allValue,count(fval) as ValueCount from
(select date,fval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select * from yourTable) as a)as a) as a
union all
select date,sval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select * from yourTable as a)as a) as a
UNION all
select date,tval from
(select date,SUBSTRING_INDEX(rplace, ' ', 1)fval,SUBSTRING_INDEX(MID(rplace,8,LENGTH(rplace)), ' ', 1)sval,SUBSTRING_INDEX(MID(rplace,15,LENGTH(rplace)), ' ', 1)tval from
(select id, date, valuelist,REPLACE(valuelist,'|',' ') as rplace from
(select * from yourTable) as a)as a) as a) as a
where fval !='' GROUP BY fval,date
2017-01-01 value1 3
2017-01-01 value2 2
2017-01-01 value3 1
欢迎来到堆栈溢出！您似乎在要求某人为您编写一些代码。堆栈溢出是一个问答网站，而不是代码编写服务。请阅读并学习如何写有效的问题。在询问之前，一定要明确，并尽最大努力。在这种情况下，您应该添加PHP@NetBlues你的价值清单中有真实的样本值吗？我编辑了你的问题，因为当你提到一个数字时，我会把它重命名为结果。但你拒绝了。如果你愿意，就创建一个过程。谢谢你的关注。这似乎仅在值的长度为6个字符时有效。但是，活动字段中的真值可能在1到16个字符之间。