T-SQL [UNION ALL] 从查询结果中删除记录

Question

有一个结合两个查询结果的简单 UNION ALL 查询。第一个查询，运行独立，returns 1208 条记录，第二个查询 14。我希望语法正确的 UNION ALL 到 return 1222 条记录，但我的下降到 896。

对我来说零意义：

SELECT a.WBS_ELEMENT_ID as [WBS Element],
a.WBS_ELEMENT_DESC as [WBS Element Desc],
a.UHC_INDUSTRY as [Industry],
a.UHC_SECTOR as [Sector],
a.UHC_DUNS_NUMBER as [UHC DUNS Number],
a.UHC_DUNS_NAME as [UHC DUNS Name],
a.PRIORITY_SUB_SECTOR as [Priority Sub Sector],
a.BUDGET_ALLOCATION as [Budget Allocation],
a.LAST_UPDATED_ON as [Last Updated]
FROM DimSectorPd a
WHERE a.wbs_element_id is not null

UNION ALL

SELECT ROW_NUMBER() OVER (ORDER BY a.wbs_element_desc) as [WBS Element],
a.WBS_ELEMENT_DESC as [WBS Element name],
a.UHC_INDUSTRY as [Industry],
a.UHC_SECTOR as [Sector],
a.UHC_DUNS_NUMBER  as [UHC DUNS Number],
a.UHC_DUNS_NAME as [UHC DUNS Name],
a.PRIORITY_SUB_SECTOR as [Priority Sub Sector],
a.BUDGET_ALLOCATION as [Budget Allocation],
a.LAST_UPDATED_ON as [Last Updated]
from dimsectorpd a where a.WBS_ELEMENT_ID is null

Answer 1

显然您的语法没有任何问题，但是如果您想尝试一种不同的方法让您的 UNION ALL 与 ROW_NUMBER 一起工作。这是：

;WITH q1
AS (
    SELECT a.WBS_ELEMENT_ID AS [WBS Element]
        ,a.WBS_ELEMENT_DESC AS [WBS Element Desc]
        ,a.UHC_INDUSTRY AS [Industry]
        ,a.UHC_SECTOR AS [Sector]
        ,a.UHC_DUNS_NUMBER AS [UHC DUNS Number]
        ,a.UHC_DUNS_NAME AS [UHC DUNS Name]
        ,a.PRIORITY_SUB_SECTOR AS [Priority Sub Sector]
        ,a.BUDGET_ALLOCATION AS [Budget Allocation]
        ,a.LAST_UPDATED_ON AS [Last Updated]
    FROM DimSectorPd a
    WHERE a.wbs_element_id IS NOT NULL

    UNION ALL

    SELECT b.WBS_ELEMENT_ID AS [WBS Element]   --just bring NULL values 
        ,b.WBS_ELEMENT_DESC AS [WBS Element name]
        ,b.UHC_INDUSTRY AS [Industry]
        ,b.UHC_SECTOR AS [Sector]
        ,b.UHC_DUNS_NUMBER AS [UHC DUNS Number]
        ,b.UHC_DUNS_NAME AS [UHC DUNS Name]
        ,b.PRIORITY_SUB_SECTOR AS [Priority Sub Sector]
        ,b.BUDGET_ALLOCATION AS [Budget Allocation]
        ,b.LAST_UPDATED_ON AS [Last Updated]
    FROM dimsectorpd b
    WHERE b.WBS_ELEMENT_ID IS NULL
    )
SELECT CASE 
        WHEN q1.[WBS Element] IS NULL
            THEN ROW_NUMBER() OVER (ORDER BY q1.WBS_Element_Desc)
        ELSE q1.[WBS Element]
        END [WBS_Element]
    ,q1.[WBS Element Desc]
    ,q1.Industry
    ,q1.Sector
    ,q1.[UHC DUNS Number]
    ,q1.[UHC DUNS Name]
    ,q1.[Priority Sub Sector]
    ,q1.[Budget Allocation]
    ,q1.[Last Updated]
FROM q1

Answer 2

这是一个简化的例子，你能看看它是否适用于你的服务器吗？

SELECT a.low AS [My ID], 
    a.name AS [My Letter]
FROM master..spt_values as a
WHERE low is not null

UNION ALL

SELECT ROW_NUMBER() OVER (ORDER BY a.name) AS [My ID],
    a.name AS [My Letter]
FROM master..spt_values as a
WHERE a.low is null

master..spt_values 在我的系统上有 2515 行...

Answer 3

您的查询应该 return table 中的所有行。除非 table 在执行之间发生变化，否则运行子查询的结果应该与运行它们与 UNION ALL.

的结果相同

注意，如果你想简化查询，那么你可以这样做：

SELECT COALESCE(a.WBS_ELEMENT_ID,
                ROW_NUMBER() OVER (PARTITION BY wbs_element_id ORDER BY a. wbs_element_desc)
               ) as [WBS Element],
       a.WBS_ELEMENT_DESC as [WBS Element Desc],
       a.UHC_INDUSTRY as [Industry],
       a.UHC_SECTOR as [Sector],
       a.UHC_DUNS_NUMBER as [UHC DUNS Number],
       a.UHC_DUNS_NAME as [UHC DUNS Name],
       a.PRIORITY_SUB_SECTOR as [Priority Sub Sector],
       a.BUDGET_ALLOCATION as [Budget Allocation],
       a.LAST_UPDATED_ON as [Last Updated]
FROM DimSectorPd a;

T-SQL [UNION ALL] 从查询结果中删除记录

T-SQL [UNION ALL] removing records from query result

sql

tsql

sql-server

unions

union-all