如何在存储过程中循环遍历 table？

Question

这个问题从演变而来。

我有两个 table 需要查询并从中收集一些计算总和；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。

两个 table 包含以下相关成员：

CustomerCategoryLog:

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

报告每月销售额:

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

对于每个单元（在两个 table 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：新的、假设的、现有的和有机。这些值是基于属于相应 "Subcategory" 字段的那些单位的所有成员的总和。 CustomerCategoryLog table 的 BeginDate/EndDate 值用于确定 Unit/Member 在 month/year 评估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                                 0
Gramps                                   
. . .

把问题用英文写成这样：

给定用户提供的月份和年份参数（例如“1”代表月份（一月），“2016”代表年份），找出每个单位有多少美元在该月内每个子类别的 MonthlySales 中（其中 BeginDate 小于或等于用户提供的 Month/Year 日期并且 EndDate 大于或等于提供的 Month/Year 日期）。

所以我似乎需要从 Year/Month 参数创建一个日期，以便与 CustomerCategoryLog table 中的 BeginDate 和 EndDate 值进行比较（另一种选择是更改 CustomerCategoryLog table，因此它具有 BeginDateMonth、BeginDateYear、EndDateMonth 和 EndDateYear 整数；但我认为必须有一种从提供的 Year/Month 参数创建日期的简单方法。

我的问题是如何在 TSQL 中实际构造它。我不是 SQL 头脑，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，但希望它足够清楚 SQL expert/jr。介意 reader 了解我需要 do/am 尝试做的事情。

更新

下面是查询的两个 table 的一些示例数据：

CustomerCategoryLog table:

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 table:

Unit = AMC THEATERS
MemberNo = 007
MonthlySales  = 8.82
CYear = 2016
Cmonth = 1

Unit = FOODBUY HMS
MemberNo = 029
MonthlySales  = ,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;

如何在存储过程中循环遍历 table？

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