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  • MySQL将一个字段中以逗号分隔的取出来形成新的字段

    1例如:要把如图1的字段拆分图2

    select  account_id,
            substring_index(substring_index(a.related_shop_ids,','
            ,b.help_topic_id+1),',',-1) shopid
        from 
            sales_hang_account a
        join
            mysql.help_topic b
            on b.help_topic_id < (length(a.related_shop_ids) -     length(replace(a.related_shop_ids,',',''))+1) 
       order by a.account_id

    2:然后和shops表进行连接查询取出我们需要的字段,我这里需要取出name

    select s.`name` as shopname,a.account_id from shops s
    inner JOIN (
    
    select  account_id,
            substring_index(substring_index(a.related_shop_ids,','
            ,b.help_topic_id+1),',',-1) shopid
        from 
            sales_hang_account a
        join
            mysql.help_topic b
            on b.help_topic_id < (length(a.related_shop_ids) -     length(replace(a.related_shop_ids,',',''))+1) 
       order by a.account_id)a on s.shop_id=a.shopid

    3:将 account_id相同合并成一行,以逗号隔开

    //这两个是网上的例子
    select ID,group_concat(NAME) as NAME from table group by ID;
    
    select ID,group_concat(NAME SEPARATOR ';') as NAME from a group by ID;
    //借助上面两个参考
    select account_id,GROUP_CONCAT(shopname SEPARATOR',')as shopname from (select s.`name` as shopname,a.account_id from shops s
    inner JOIN (
    
    select  account_id,
            substring_index(substring_index(a.related_shop_ids,','
            ,b.help_topic_id+1),',',-1) shopid
        from 
            sales_hang_account a
        join
            mysql.help_topic b
            on b.help_topic_id < (length(a.related_shop_ids) -     length(replace(a.related_shop_ids,',',''))+1) 
       order by a.account_id)a on s.shop_id=a.shopid) a GROUP BY account_id

    效果如下

    第二种方法

    select g.account_id,g.related_shop_ids,GROUP_CONCAT(s.name)as shopname from sales_hang_account g left join shops s on FIND_IN_SET(s.shop_id , g.related_shop_ids)
    GROUP BY g.account_id

     SqlServer

     [Product] -- 该字段存储格式为 7,8,9,11,10,12 ,数据类型为nvarchar
    select
    id,ProductName=stuff((select ',' + product_chinaname from base_supplier_product where charindex(','+ltrim(productid)+',',','+ Product + ',') > 0 for xml path('') ), 1, 1, '') FROM base_Pre_sale_project

    结果

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  • 原文地址:https://www.cnblogs.com/weixin18/p/9827222.html
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