&引用；“动态”；sql server 2008 r2中的where语句

我需要根据select语句中的结果传递两个不同的

WHERE

语句。我的基本查询如下

SELECT table1.taskID, 
    table1.startTime, 
    table1.endTime, 
    table1.everyMinutes, 
    table3.dlid, 
    table3.run 
FROM table1
JOIN table2
    ON table1.taskID = table2.taskID
LEFT JOIN table3
    ON table1.taskID = table3.taskID
WHERE table2.active = '1'
ORDER BY taskID ASC

CONVERT(DATE,GETDATE()) IN (SELECT dldate FROM table4 WHERE dlid = table3.dlid)

CONVERT(DATE,GETDATE()) NOT IN (SELECT dldate FROM table4 WHERE dlid = table3.dlid)

我正在努力解决的是，如果

table3.run='1'

，那么我需要包括以下内容

SELECT table1.taskID, 
    table1.startTime, 
    table1.endTime, 
    table1.everyMinutes, 
    table3.dlid, 
    table3.run 
FROM table1
JOIN table2
    ON table1.taskID = table2.taskID
LEFT JOIN table3
    ON table1.taskID = table3.taskID
WHERE table2.active = '1'
ORDER BY taskID ASC

CONVERT(DATE,GETDATE()) IN (SELECT dldate FROM table4 WHERE dlid = table3.dlid)

CONVERT(DATE,GETDATE()) NOT IN (SELECT dldate FROM table4 WHERE dlid = table3.dlid)

如果

table3.run='0'

我需要以下内容

SELECT table1.taskID, 
    table1.startTime, 
    table1.endTime, 
    table1.everyMinutes, 
    table3.dlid, 
    table3.run 
FROM table1
JOIN table2
    ON table1.taskID = table2.taskID
LEFT JOIN table3
    ON table1.taskID = table3.taskID
WHERE table2.active = '1'
ORDER BY taskID ASC

CONVERT(DATE,GETDATE()) IN (SELECT dldate FROM table4 WHERE dlid = table3.dlid)

CONVERT(DATE,GETDATE()) NOT IN (SELECT dldate FROM table4 WHERE dlid = table3.dlid)

最后，如果table3.run='NULL'，那么我不需要这两条语句

SELECT table1.taskID, 
    table1.startTime, 
    table1.endTime, 
    table1.everyMinutes, 
    table3.dlid, 
    table3.run 
FROM table1
JOIN table2
     ON table1.taskID = table2.taskID
LEFT JOIN table3
    ON table1.taskID = table3.taskID
WHERE table2.active = '1'
    AND (
            (table3.run = '1' 
             and CONVERT(DATE,GETDATE()) 
             IN (SELECT dldate FROM table4 WHERE dlid = table3.dlid)) 

         or (table3.run = '0' 
             and CONVERT(DATE,GETDATE()) NOT IN 
            (SELECT dldate FROM table4 WHERE dlid = table3.dlid))

         or table3.run = 'NULL'   -- incredibly bad idea
         )
ORDER BY taskID ASC

---

这是如何处理

table3.run='NULL'

的情况的？仔细看看。OP专门使用字符串

'NULL'

，而不是真正的（TM）

NULL

。您的代码应该使用

table3.run='NULL'

来满足OP，但是您使用了

NULL

的相等性测试，而不是

is NULL

。（我会让你用OP上的湿面条来测试一个空字符串。）@HABO谁会在头脑正常的情况下测试一个值为空的字符串？这几乎和在某些语言中合法的if=then=else一样糟糕。谢谢你的耐心，我正在学习。所以那些看起来像小整数或位的引用值不会打扰你吗？唉<代码>0，

1

或

错误\u成功

。