Sql server 选择满足条件的所有值和一些附加值

我有一个带有字段的表：

| Accompanying measures (bool) | Category (String) | Instrument (String) |

因为应用程序的设计并不是要真正替换这些，所以我使用ValidUntil Date类型字段更改了table Instrument，该字段的日期要么是不推荐使用的日期，要么是NULL（如果仍然有效）。 视图显示旧数据和新数据的混合。旧数据可能包含已弃用的工具，而新数据则不会。 如果我只显示新仪器ValidUntil为空，我将中断页面，因为有选定的伴随测量无法显示，因为它们无法从数据库检索

Tl；博士 编辑：如何选择所有ValidUntil为空以及ValidUntil！=NULL，但hasbeenselectedasaccompanymeasure为true

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如果我理解您的问题，您必须使用UNION ALL/UNION组合两种不同条件的数据集

--ValidUntil IS NULL
SELECT
    a.AccompanyingMeasureID, a.InstrumentID, a.TaskID,         
    a.HasBeenSelectedAsAccompanyingMeasure, a.CategoryID
    , i.Name AS InstrumentName,     ic.Name AS CategoryName
FROM wc_AccompanyingMeasures AS a 
INNER JOIN wc_Instruments AS i ON a.InstrumentID = i.ID 
INNER JOIN wc_InstrumentCategories AS ic ON i.CategoryID = ic.ID
WHERE (a.TaskID = @TaskID) 
AND (i.ValidUntil IS NULL) 
UNION ALL
--ValidUntil != NULL, but HasBeenSelectedAsAccompanyingMeasure is true
SELECT
    a.AccompanyingMeasureID, a.InstrumentID, a.TaskID,         
    a.HasBeenSelectedAsAccompanyingMeasure, a.CategoryID
    , i.Name AS InstrumentName,     ic.Name AS CategoryName
FROM wc_AccompanyingMeasures AS a 
INNER JOIN wc_Instruments AS i ON a.InstrumentID = i.ID 
INNER JOIN wc_InstrumentCategories AS ic ON i.CategoryID = ic.ID
WHERE (a.TaskID = @TaskID) 
AND (i.ValidUntil IS NOT NULL AND HasBeenSelectedAsAccompanyingMeasure='TRUE')

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现在还不清楚你到底在找什么。你能在TL:DR之后澄清一下位吗？

--ValidUntil IS NULL
SELECT
    a.AccompanyingMeasureID, a.InstrumentID, a.TaskID,         
    a.HasBeenSelectedAsAccompanyingMeasure, a.CategoryID
    , i.Name AS InstrumentName,     ic.Name AS CategoryName
FROM wc_AccompanyingMeasures AS a 
INNER JOIN wc_Instruments AS i ON a.InstrumentID = i.ID 
INNER JOIN wc_InstrumentCategories AS ic ON i.CategoryID = ic.ID
WHERE (a.TaskID = @TaskID) 
AND (i.ValidUntil IS NULL) 
UNION ALL
--ValidUntil != NULL, but HasBeenSelectedAsAccompanyingMeasure is true
SELECT
    a.AccompanyingMeasureID, a.InstrumentID, a.TaskID,         
    a.HasBeenSelectedAsAccompanyingMeasure, a.CategoryID
    , i.Name AS InstrumentName,     ic.Name AS CategoryName
FROM wc_AccompanyingMeasures AS a 
INNER JOIN wc_Instruments AS i ON a.InstrumentID = i.ID 
INNER JOIN wc_InstrumentCategories AS ic ON i.CategoryID = ic.ID
WHERE (a.TaskID = @TaskID) 
AND (i.ValidUntil IS NOT NULL AND HasBeenSelectedAsAccompanyingMeasure='TRUE')