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[MySQL]错误1248（42000）：每个派生表都必须有自己的别名

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[MySQL]错误1248（42000）：每个派生表都必须有自己的别名,mysql,sql,Mysql,Sql,我试图找出工艺长度的最大值/最小值/平均值/每个配方的步骤数以及使用配方的晶片数。 该表很大，并且是按时间单位记录的，因此存在大量重复数据，如配方或配方步骤。 这是我的代码，请帮助我： select distinct recipe as recipe_id, max(pl) as max_process_length, min(pl) as min_process_length, avg(pl) as avg_process_length, ma

我试图找出工艺长度的最大值/最小值/平均值/每个配方的步骤数以及使用配方的晶片数。 该表很大，并且是按时间单位记录的，因此存在大量重复数据，如配方或配方步骤。 这是我的代码，请帮助我：

select distinct 
    recipe as recipe_id, 
    max(pl) as max_process_length, 
    min(pl) as min_process_length, 
    avg(pl) as avg_process_length, 
    max(steps) as max_number_of_steps, 
    min(steps) as min_number_of_steps, 
    avg(steps) as avg_number_of_steps, 
    count(wfr_id) as number_of_wafers
into outfile 'C:/ProgramData/MySQL/MySQL Server 8.0/Uploads/process_id.xls'
from 01m02train 
group by recipe
having (
    max(pl) = (
        select max(pt) 
        from (
            select count(time) as pt 
            from 01m02train 
            group by (recipe,wfr_id)
        )
    ) as `maxpl` 
    and min(pl) = (
        select min(pt) 
        from (
            select count(time) as pt 
            from 01m02train 
            group by (recipe,wfr_id)
        )
    ) as `minpl` 
    and avg(pl) = (
        select avg(pt) 
        from (
            select count(time) as pt 
            from 01m02train 
            group by (recipe,wfr_id)
        )
    ) as `avgpl` 
    and max(steps) = (
        select max(rs) 
        from (
            select distinct count(recipe_step) as rs 
            from 01m02train 
            group by (recipe,wfr_id)
        )
    ) as `maxrs` 
    and min(steps) = (
        select min(rs) 
        from (
            select distinct count(recipe_step) as rs 
            from 01m02train 
            group by (recipe,wfr_id)
        )
    ) as `minrs` 
    and avg(steps) = (
        select avg(rs) 
        from (
            select distinct count(recipe_step) as rs 
            from 01m02train 
            group by (recipe,wfr_id)
        )
    ) as `avgrs`
);
在having comparison子句中，放置的位置太多（），并且这些位置不会解析子查询的表名别名

having ( max(pl)=( <----  this must removed 
    select max(pt) from ( 
        select count(time) as pt 
        from 01m02train 
        group by (recipe,wfr_id)
    ) <---- this must removed 
) as `maxpl` 
and min(pl)=( <----  this must removed 
    select min(pt) from (  
        select count(time) as pt 
        from 01m02train 
        group by (recipe,wfr_id) 
      )<---- this must removed 
  ) as `minpl` and
  ..... 
  ....  

having（max（pl）=（在having comparison子句中，您放置的位置太多（），这些不会解析子查询的表名别名


having ( max(pl)=( <----  this must removed 
    select max(pt) from ( 
        select count(time) as pt 
        from 01m02train 
        group by (recipe,wfr_id)
    ) <---- this must removed 
) as `maxpl` 
and min(pl)=( <----  this must removed 
    select min(pt) from (  
        select count(time) as pt 
        from 01m02train 
        group by (recipe,wfr_id) 
      )<---- this must removed 
  ) as `minpl` and
  ..... 
  ....  



having（max（pl）=（主要问题：错误消息非常清楚，您需要对表达式中生成的派生表进行别名。另一方面，对条件进行别名是没有意义的。因此基本上：


max(pl) = (
    select max(pt) 
    from (
        select count(time) as pt 
        from 01m02train 
        group by (recipe,wfr_id)
    )
) as `maxpl` 


应将其拼写为：


max(pl) = (
    select max(pt) 
    from (
        select count(time) as pt 
        from 01m02train 
        group by (recipe,wfr_id)
    ) as `maxpl`
)  


其他问题（它们不会产生错误，但在我看来，仍然值得注意）：


    

  • group by
    子句中枚举的列周围不需要括号（这是多余的）
    • 

  • having
    子句中的条件也是如此（除非您将
    和
    与
    或
    混合在一起，而您不这样做）
    • 

  • select distinct
    with
    groupby
    没有意义（两者本质上都是聚合）
    • 


以下是您的查询的更新版本：


select 
    recipe as recipe_id, 
    max(pl) as max_process_length, 
    min(pl) as min_process_length, 
    avg(pl) as avg_process_length, 
    max(steps) as max_number_of_steps, 
    min(steps) as min_number_of_steps, 
    avg(steps) as avg_number_of_steps, 
    count(wfr_id) as number_of_wafers
into outfile 'C:/ProgramData/MySQL/MySQL Server 8.0/Uploads/process_id.xls'
from 01m02train 
group by recipe
having 
    max(pl) = (
        select max(pt) 
        from (
            select count(time) as pt 
            from 01m02train 
            group by (recipe,wfr_id)
        ) as `maxpl` 
    ) 
    and min(pl) = (
        select min(pt) 
        from (
            select count(time) as pt 
            from 01m02train 
            group by (recipe,wfr_id)
        ) as `minpl` 
    ) 
    and avg(pl) = (
        select avg(pt) 
        from (
            select count(time) as pt 
            from 01m02train 
            group by (recipe,wfr_id)
        ) as `avgpl` 
    ) 
    and max(steps) = (
        select max(rs) 
        from (
            select count(recipe_step) as rs 
            from 01m02train 
            group by (recipe,wfr_id)
        ) as `maxrs` 
    ) 
    and min(steps) = (
        select min(rs) 
        from (
            select count(recipe_step) as rs 
            from 01m02train 
            group by (recipe,wfr_id)
        ) as `minrs`
    )  
    and avg(steps) = (
        select avg(rs) 
        from (
            select count(recipe_step) as rs 
            from 01m02train 
            group by (recipe,wfr_id)
        ) as `avgrs`
    ) 
;



主要问题：错误消息非常清楚，您需要对表达式中生成的派生表进行别名。另一方面，对条件进行别名是没有意义的。因此基本上：


max(pl) = (
    select max(pt) 
    from (
        select count(time) as pt 
        from 01m02train 
        group by (recipe,wfr_id)
    )
) as `maxpl` 


应将其拼写为：


max(pl) = (
    select max(pt) 
    from (
        select count(time) as pt 
        from 01m02train 
        group by (recipe,wfr_id)
    ) as `maxpl`
)  


其他问题（它们不会产生错误，但在我看来，仍然值得注意）：


    

  • group by
    子句中枚举的列周围不需要括号（这是多余的）
    • 

  • having
    子句中的条件也是如此（除非您将
    和
    与
    或
    混合在一起，而您不这样做）
    • 

  • select distinct
    with
    groupby
    没有意义（两者本质上都是聚合）
    • 


以下是您的查询的更新版本：


select 
    recipe as recipe_id, 
    max(pl) as max_process_length, 
    min(pl) as min_process_length, 
    avg(pl) as avg_process_length, 
    max(steps) as max_number_of_steps, 
    min(steps) as min_number_of_steps, 
    avg(steps) as avg_number_of_steps, 
    count(wfr_id) as number_of_wafers
into outfile 'C:/ProgramData/MySQL/MySQL Server 8.0/Uploads/process_id.xls'
from 01m02train 
group by recipe
having 
    max(pl) = (
        select max(pt) 
        from (
            select count(time) as pt 
            from 01m02train 
            group by (recipe,wfr_id)
        ) as `maxpl` 
    ) 
    and min(pl) = (
        select min(pt) 
        from (
            select count(time) as pt 
            from 01m02train 
            group by (recipe,wfr_id)
        ) as `minpl` 
    ) 
    and avg(pl) = (
        select avg(pt) 
        from (
            select count(time) as pt 
            from 01m02train 
            group by (recipe,wfr_id)
        ) as `avgpl` 
    ) 
    and max(steps) = (
        select max(rs) 
        from (
            select count(recipe_step) as rs 
            from 01m02train 
            group by (recipe,wfr_id)
        ) as `maxrs` 
    ) 
    and min(steps) = (
        select min(rs) 
        from (
            select count(recipe_step) as rs 
            from 01m02train 
            group by (recipe,wfr_id)
        ) as `minrs`
    )  
    and avg(steps) = (
        select avg(rs) 
        from (
            select count(recipe_step) as rs 
            from 01m02train 
            group by (recipe,wfr_id)
        ) as `avgrs`
    ) 
;



简化问题（参见）。格式良好的SQL更容易阅读和编写。我修改了您的查询。如JARLH评论的，请考虑在下次发布之前自己做……简化问题（查看）。此外，格式良好的SQL更容易阅读和编写。我重新修改了您的查询。如JARLH评论的，请考虑在下次发布之前自己做。