SQL - 总结每月销售数据(SQL - Summarizing Monthly Sales Data)

 我有两个表需要合并，但我无法看到联接起作用。 图片有三张桌子 
 
 _date_array2：有一个DateMonthYr字段，其中包含所有可能的日期/年份组合 
 
 _sales_summ_tbl__ =>有5个字段。 只有销售月份出现。 例如，您将看到只有三条记录显示在第二个表格中。 例如，没有5/2016，因为那个月没有销售。 
 
 我的目标是“填充”第二个表，使TotalDemand为0，持续几个月没有销售。 我非常接近（请参阅第三张表格），但我无法让PartNumber显示在没有销售的日期。 
 
 我的猜测是这是由于RIGHT JOIN。 但我不知道如何处理这个问题。 我希望的输出是表3，但所有条目都填入了部件号。 
 
  
 
 这里是我的代码（运行此代码的结果是图片中的第三个/最后一个表）： 
 
SELECT TmpSalesTbl.PartNumber as PartNumber,
tmp_date_array.CreateDateMonth as CreateDateMonth,
tmp_date_array.CreateDateYear as CreateDateYear,
CASE WHEN TmpSalesTbl.TotalDemand is NULL THEN 0 ELSE TmpSalesTbl.TotalDemand END as TotalDemand
FROM #_sales_summ_tbl__ TmpSalesTbl
RIGHT JOIN #_date_array2 tmp_date_array on tmp_date_array.CreateDateMonthYr = TmpSalesTbl.CreateDateMonthYr
ORDER BY tmp_date_array.CreateDateYear, tmp_date_array.CreateDateMonth

I have two tables that I need to combine, but I can't get to seem the joins to work. The picture has three tables
 
_date_array2: Has a field DateMonthYr that contains all possible date/yr combinations
 
_sales_summ_tbl__ => Has 5 fields. Only months with sales show up. For example, you see only three records showing up for the second table. There is no 5/2016, for example, because there were no sales for that month.
 
My goal is to "pad" the second table to have TotalDemand of 0's for months with no sales. I am very close (see the third table), except I cannot get the PartNumber to show up for dates with no sales.
 
My guess is that it's due to the RIGHT JOIN. But I'm not sure how to handle this. The output I am hoping for is table 3 but with the part number populated for all entries.
 
 
And here is my code (the results from running this code are the third/last table in the picture):
 
SELECT TmpSalesTbl.PartNumber as PartNumber,
tmp_date_array.CreateDateMonth as CreateDateMonth,
tmp_date_array.CreateDateYear as CreateDateYear,
CASE WHEN TmpSalesTbl.TotalDemand is NULL THEN 0 ELSE TmpSalesTbl.TotalDemand END as TotalDemand
FROM #_sales_summ_tbl__ TmpSalesTbl
RIGHT JOIN #_date_array2 tmp_date_array on tmp_date_array.CreateDateMonthYr = TmpSalesTbl.CreateDateMonthYr
ORDER BY tmp_date_array.CreateDateYear, tmp_date_array.CreateDateMonth

原文：https://stackoverflow.com/questions/47564078