Question

我在理解和使用T-SQL（SQL Server 2012）中的嵌套子查询时遇到了很大的困难：

客户名称
客户编号
首次销售日期
最后销售日期

我可以使用以下查询创建显示EITHER最小值（销售日期）或最大值（销售日期）的表，

'odds'

请帮助。我知道这是一个初学者的问题。

Answer 1

select * into #fact_invoice_history from
    (select 1 as cm_number, 'one' as cm_name, '2018-09-01 10:15:00' as dim_invoice_date
    union all select 1, 'one', '2018-09-02 10:15:00'
    union all select 1, 'one', '2018-09-03 10:15:00'
    union all select 2, 'two', '2018-09-06 10:15:00'
    union all select 2, 'two', '2018-09-07 10:15:00'
    union all select 3, 'three', '2018-09-08 10:15:00') data

select * from #fact_invoice_history
-- ----------------------------------------
--  cm_number   cm_name dim_invoice_date
--  ----------- ------- -------------------
--  1           one     2018-09-01 10:15:00
--  1           one     2018-09-02 10:15:00
--  1           one     2018-09-03 10:15:00
--  2           two     2018-09-06 10:15:00
--  2           two     2018-09-07 10:15:00
--  3           three   2018-09-08 10:15:00
-- ----------------------------------------

select 
    cm_number,
    cm_name,
    min(dim_invoice_date) min_sale_date,
    max(dim_invoice_date) max_sale_date
from 
    #fact_invoice_history
group by
    cm_number,
    cm_name
-- ------------------------------------------------------------
--  cm_number   cm_name min_sale_date       max_sale_date
--  ----------- ------- ------------------- -------------------
--  1           one     2018-09-01 10:15:00 2018-09-03 10:15:00
--  3           three   2018-09-08 10:15:00 2018-09-08 10:15:00
--  2           two     2018-09-06 10:15:00 2018-09-07 10:15:00
-- ------------------------------------------------------------

drop table #fact_invoice_history

Answer 2

以下解决方案效果很好。

    select 
    cm_number,
    cm_name,
    min(dim_invoice_date) min_sale_date,
    max(dim_invoice_date) max_sale_date
from 
    #fact_invoice_history
group by
    cm_number,
    cm_name

虽然我可能在这里问了一个错误的问题，但感谢您的帮助

具有最小值和最大值的SQL Server子查询

2 个答案: