Question

我正在试图弄清楚如何在where子句中返回可能的多个值。

这是我的查询

SELECT *, 
                            ISNULL(nStatus, '0') Status,
                            ISNULL(dtUsed, 0) dtUsed,
                            ISNULL(sStaffID, '') StaffID,
                            ISNULL((SELECT sName FROM GCS_tbBranch WHERE nSeq=GCS_tbGC.nBranchNo), '') nBranchName,
                            ISNULL((SELECT dtValidEnd FROM GCS_tbGCGroup WHERE nGroupNo = GCS_tbGC.nGroupSeq), 0) dtValidUntil,
                            ISNULL((SELECT dtCreated FROM GCS_tbGCGroup WHERE nGroupNo=GCS_tbGC.nGroupSeq), 0) dtCreated, 
                            ISNULL((SELECT nPrice FROM GCS_tbGCGroup WHERE nGroupNo=GCS_tbGC.nGroupSeq), 0) nPrice,
                            ISNULL(sRemarks, ' ') sRemarks 
                            FROM GCS_tbGC WHERE sGCNo LIKE @sGCNo+'%' AND nGroupSeq IN (SELECT nGroupNo FROM GCS_tbGCGroup WHERE
                            CASE
                            WHEN @sClass = 'QNS' OR @sClass = 'IFL' THEN (sClass = 'QNS' OR sClass = 'IFL')
                            ELSE
                            @sClass
                            END
                            )

其中，如果变量@sClass持有'QNS' or 'IFL'，它将返回具有sClass = 'QNS' OR sClass = 'IFL'的记录，否则，只返回@sClass变量的值。

编辑：每当我运行此查询时，它都会返回此异常

Incorrect syntax near ' = ' is invalid.

Answer 1

我认为CASE表达式不适合这项工作。请尝试以下查询。

SELECT *, 
                            ISNULL(nStatus, '0') Status,
                            ISNULL(dtUsed, 0) dtUsed,
                            ISNULL(sStaffID, '') StaffID,
                            ISNULL((SELECT sName FROM GCS_tbBranch WHERE nSeq=GCS_tbGC.nBranchNo), '') nBranchName,
                            ISNULL((SELECT dtValidEnd FROM GCS_tbGCGroup WHERE nGroupNo = GCS_tbGC.nGroupSeq), 0) dtValidUntil,
                            ISNULL((SELECT dtCreated FROM GCS_tbGCGroup WHERE nGroupNo=GCS_tbGC.nGroupSeq), 0) dtCreated, 
                            ISNULL((SELECT nPrice FROM GCS_tbGCGroup WHERE nGroupNo=GCS_tbGC.nGroupSeq), 0) nPrice,
                            ISNULL(sRemarks, ' ') sRemarks 
FROM GCS_tbGC 
WHERE sGCNo LIKE @sGCNo+'%' 
AND nGroupSeq IN (
    SELECT nGroupNo 
    FROM GCS_tbGCGroup 
    WHERE
        @sClass IN('QNS', 'IFL') AND sClass IN('QNS', 'IFL')
    UNION ALL
    SELECT @sClass
    WHERE
        @sClass NOT IN('QNS', 'IFL')
    );

Answer 2

CASE会返回标量并且应该像一个一样使用 - 您无法按照自己的方式操纵条件。
尝试更简单的表达式：

and (
    nGroupSeq = @sClass 
    or @sClass = 'QNS' and nGroupSeq = 'IFL'
    or @sClass = 'IFL' and nGroupSeq = 'QNZ'
)

或

and (
    nGroupSeq = @sClass 
    or @sClass in ('QNS', 'IFL') and nGroupSeq in ('QNS', 'IFL'))
)

Answer 3

管理将其关闭。

认为我可以在IN关键字中插入case语句，我可以根据情况使用2个case语句。

这是我的解决方案。

SELECT *, 
                            ISNULL(nStatus, '0') Status,
                            ISNULL(dtUsed, 0) dtUsed,
                            ISNULL(sStaffID, '') StaffID,
                            ISNULL((SELECT sName FROM GCS_tbBranch WHERE nSeq=GCS_tbGC.nBranchNo), '') nBranchName,
                            ISNULL((SELECT dtValidEnd FROM GCS_tbGCGroup WHERE nGroupNo = GCS_tbGC.nGroupSeq), 0) dtValidUntil,
                            ISNULL((SELECT dtCreated FROM GCS_tbGCGroup WHERE nGroupNo=GCS_tbGC.nGroupSeq), 0) dtCreated, 
                            ISNULL((SELECT nPrice FROM GCS_tbGCGroup WHERE nGroupNo=GCS_tbGC.nGroupSeq), 0) nPrice,
                            ISNULL(sRemarks, ' ') sRemarks 
                            FROM GCS_tbGC WHERE sGCNo LIKE @sGCNo+'%' AND nGroupSeq IN (SELECT nGroupNo FROM GCS_tbGCGroup WHERE sClass IN (
                            CASE @sClass
                            WHEN 'QNS' THEN 'IFL'
                            WHEN 'IFL' THEN 'IFL'
                            ELSE
                            @sClass
                            END
                            ,
                            CASE @sClass
                            WHEN 'QNS' THEN 'QNS'
                            WHEN 'IFL' THEN 'QNS'
                            ELSE
                            ''
                            END
                            )
                            )

欢迎任何更好的查询。我希望你能提出进一步缩短/增强查询的建议。谢谢，更有力量！

使用case语句在where子句中返回多个结果

3 个答案: