SQL 根据列中的值显示结果

Question

所以我在网络 SQL 中有 2 个 table，其中一个看起来像这样（有几千行）：

    customer_number        |       order_number
--------------------------------------------
1234                              12
1234                              13
1234                              14
6793                              20
6793                              22
3210                              53

etc.

而另一个 table 像这样（也是数千行）：

customer_number        |       first_purchase_year
----------------------------------------------------
1234                              2010
5313                              2001
1632                              2018
9853                              2017
6793                              2000
3210                              2005

etc.

我将此代码发送给前 select 10 位客户 table 并列出他们所有的购买：

select top 10 * from
(select distinct t1.customer_number, 
    stuff((select '' + t2.order_number
                from orders t2
                where t1.customer_number = t2.customer_number
                for xml path(''), type
                ).value('.','NVARCHAR(MAX)')
            ,1,0,'')DATA
from orders t1) a

Whch 输出这个：

    customer_number        |       order_number
--------------------------------------------
1234                              12 13 14
6793                              20 22
3210                              53

我需要做的是只显示 first_purchase_year > 2010 的 10 个随机客户。我不确定如何检查对应于 customer_number 的 first_purchase_year 是否大于 2010。谢谢！

Answer 1

你只需要修复外from子句中的子查询：

select c.customer_number, 
       stuff((select '' + o2.order_number
              from orders o2
              where c.customer_number = o2.customer_number
              for xml path(''), type
             ).value('.','NVARCHAR(MAX)'
                    ), 1, 0, ''
            ) as data
from (select top (10) c.customer_number
      from table2 c
      where c.first_purchase_year > 2010
     ) c;

SQL 根据列中的值显示结果

SQL displaying results based on a value in column

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