sql-server - 如何在存储过程中循环遍历表？

Question

这个问题是从this one演变而来的.

我有两个表需要查询并从中收集一些计算所得的总和；我需要一个基于单位的结果集——每个单位一行，并将它们的计算数据折叠到该行中。

这两个表包含以下相关成员:

客户类别日志:

Unit        varchar(25)
MemberNo    varchar(10)
Category    varchar(50)
Subcategory varchar(50)
BeginDate   Datetime
EndDate     Datetime

ReportingMonthlySales:

Unit (VarChar)
MemberNo (VarChar)
MonthlySales (Money)
CYear (Int)
Cmonth (Int)

对于每个单位(在两个表中都有很多行，每个 MemberNo 一个，但在结果集中包含一行)，我需要填充四列:New、Assumed、Existing 和 Organic。这些值是基于属于相应“子类别”字段的成员的单元的所有成员的总和。 CustomerCategoryLog 表的 BeginDate/EndDate 值用于确定单位/成员在被评估的月/年期间属于哪个子类别。

结果集的简化形式如下所示:

Unit    New  Assumed        Existing    Organic     Total
----    ---  -------        --------    -------     -----
Abuelos $22  $44            $33         $11         $110
Gramps  $12  $23            $1          $34         $70
. . .

如果用英语来表达这个问题，它是这样的:

给定用户提供的月份和年份作为参数(例如“1”代表月份(一月)，“2016”代表年份)，找出每个单位的每月销售额中有多少美元该月内的子类别(其中 BeginDate 小于或等于用户提供的月/年日期且 EndDate 大于或等于提供的月/年日期)。

因此，我似乎需要根据年/月参数创建一个日期，以便与 CustomerCategoryLog 表中的 BeginDate 和 EndDate 值进行比较(另一种选择是更改 CustomerCategoryLog 表，使其具有 BeginDateMonth， BeginDateYear、EndDateMonth 和 EndDateYear 整数；但我认为必须有一种简单的方法来根据提供的年/月参数创建日期。

我的问题是如何在 TSQL 中实际构造它。我不是 SQLhead，我最好的(伪 SQL)是:

DECLARE @Unit varchar(30);
DECLARE @Year Int;
DECLARE @Month Int;
. . .
DECLARE @PARAMDATE DATETIME = (Year + Month + 01).ToDateTime();

SELECT DISTINCT UNIT INTO #UNITS U FROM ReportingMonthlySales
WHILE NOT U.EOF DO

Unit = U.Unit

SELECT Unit, MonthlySales as 'NewSales' FROM (SELECT MonthlySales FROM ReportingMonthlySales RMS left join     
CustomerCategoryLog CCL on RMS.Unit = CCL.Unit WHERE RMS.Unit = Unit AND RMS.CYear = @Year and RMS.CMonth = @Month     
AND CCL.BeginDate >= PARAMDATE AND CCL.EndDate <= PARAMDATE AND CCL.Subcategory = 'New'),

MonthlySales as 'AssumedSales' FROM (SELECT MonthlySales FROM ReportingMonthlySales RMS left join     
CustomerCategoryLog CCL on RMS.Unit = CCL.Unit WHERE RMS.Unit = Unit AND  RMS.CYear = @Year and RMS.CMonth = @Month     
AND CCL.BeginDate >= PARAMDATE AND CCL.EndDate <= PARAMDATE AND CCL.Subcategory = 'Assumed'),

MonthlySales as 'ExistingSales' FROM (SELECT MonthlySales FROM ReportingMonthlySales RMS left join     
CustomerCategoryLog CCL on RMS.Unit = CCL.Unit WHERE RMS.Unit = Unit AND  RMS.CYear = @Year and RMS.CMonth = @Month     
AND CCL.BeginDate >= PARAMDATE AND CCL.EndDate <= PARAMDATE AND CCL.Subcategory = 'Existing'),

MonthlySales as 'OrganicSales' FROM (SELECT MonthlySales FROM ReportingMonthlySales RMS left join     
CustomerCategoryLog CCL on RMS.Unit = CCL.Unit WHERE RMS.Unit = Unit AND  RMS.CYear = @Year and RMS.CMonth = @Month     
AND CCL.BeginDate >= PARAMDATE AND CCL.EndDate <= PARAMDATE AND CCL.Subcategory = 'Organic')
FROM ReportingMonthlySales RMS2
ORDER BY RMS2.Unit

END WHILENOTEOF

我知道这不太正确，甚至可能不太正确，但希望它对 SQL 专家/jr 来说足够清楚。读心者了解我需要做什么/正在尝试做什么。

更新

下面是查询的两个表中的一些示例数据:

CustomerCategoryLog 表:

MemberNo = 007
Unit = AMC THEATERS
Subcategory = New
BeginDate = 1/1/2016
EndDate = 12/31/2016

MemberNo = 029
Unit = FOODBUY HMS
Subcategory = Existing
BeginDate = 1/1/2015
EndDate = 12/31/2015

ReportingMonthlySales 表:

Unit = AMC THEATERS
MemberNo = 007
MonthlySales  = $988.82
CYear = 2016
Cmonth = 1

Unit = FOODBUY HMS
MemberNo = 029
MonthlySales  = $61,479.28
CYear = 2017
Cmonth = 3

Answer 1

这看起来像是一个漫长的转折点。

这样的事情怎么样？

declare @Unit varchar(30);
declare @Year int;
declare @Month int;
declare @paramdate datetime = datefromparts(@year, @month, 1);
/* --prior to sql server 2012
declare @paramdate datetime;
set @paramdate = convert(datetime,convert(char(4),@Year)
                +right('0'+convert(varchar(2),@month),2)
                +'01') 
*/

select distinct unit
into #Units
from ReportingMonthlySales;

select 
    u.Unit
  , New      = sum(case when ccl.Subcategory = 'New'      then rms.MonthlySales else 0 end)
  , Assumed  = sum(case when ccl.Subcategory = 'Assumed'  then rms.MonthlySales else 0 end)
  , Existing = sum(case when ccl.Subcategory = 'Existing' then rms.MonthlySales else 0 end)
  , Organic  = sum(case when ccl.Subcategory = 'Organic'  then rms.MonthlySales else 0 end)
from #Units u
  left join CustomerCategoryLog ccl 
    on u.Unit = ccl.Unit
   and @paramdate >= ccl.begindate
   and @paramdate <= ccl.enddate
  left join ReportingMonthlySales rms
    on u.Unit = rms.Unit
   and rms.cyear  = @year
   and rms.cmonth = @month
group by u.unit;