SQL連接問題澄清

Question

我有兩個表。客戶（客戶，公司，州，地位）和支持狀態（客戶，公司，地位，協議）。下面的查詢是否應該返回協議值爲0且狀態不等於「禁用」的所有公司？ 我很困惑，因爲我正在選擇公司，我正在加入，這兩個表由公共因素（clientid）組成，我正在篩選查詢的結果。

SELECT cl.company 
FROM clients cl 
     INNER JOIN supportstatus su 
     ON cl.clientid = su.clientid 
WHERE su.agreement11 = 0 
     AND su.status <> 'disabled' 
ORDER BY cl.company 

的ColdFusion源

<cfquery name="qryPendingAgreement" datasource="support"> 
SELECT clientid 
FROM supportstatus 
WHERE agreement11 = 0 AND status <> 'disabled' 
</cfquery> 

<cfquery name="qryClient" datasource="support"> 
SELECT  clientid, company, state, serv_billing 
FROM   clients 
WHERE prod_arth = 1 OR prod_artr = 1 OR prod_epcr_host = 1 OR prod_epcr_remote = 1 OR prod_billing = 1 OR prod_collections = 1 
</cfquery> 

<cfquery name="qryResults" dbtype="query"> 
SELECT qryClient.company, qryClient.state, qryClient.serv_billing 
FROM qryPendingAgreement, qryClient 
WHERE qryPendingAgreement.clientid = qryClient.clientid 
order by qryClient.company 
</cfquery> 

Answer 1

這是胡亂猜測，但如果你正在使用這個版本：

SELECT cl.company 
FROM clients cl 
     INNER JOIN supportstatus su 
     ON cl.clientid = su.clientid 
WHERE su.agreement11 = 0 
     AND su.status <> 'disabled' 
     OR prod_arth = 1  OR prod_artr = 1 
     OR prod_epcr_host = 1 OR prod_epcr_remote = 1 
     OR prod_billing = 1 OR prod_collections = 1 
ORDER BY cl.company 

的問題是AND,OR優先。試試這個：

SELECT cl.company 
FROM clients cl 
     INNER JOIN supportstatus su 
     ON cl.clientid = su.clientid 
WHERE su.agreement11 = 0 
     AND su.status <> 'disabled' 
     AND (prod_arth = 1  OR prod_artr = 1 
      OR prod_epcr_host = 1 OR prod_epcr_remote = 1 
      OR prod_billing = 1 OR prod_collections = 1 
      ) 
ORDER BY cl.company 

Answer 2

你沒說什麼結果的查詢是給你的。如果查詢過濾的行數多於您認爲的數量，則答案可能是三值邏輯。

null != 'disabled' - >null，這是不正確的，該行被過濾。

請嘗試使用此過濾器。

WHERE su.agreement11 = 0 
    AND isnull(su.status,'') <> 'disabled' 

Answer 3

這應該有助於您測試您的查詢。你的問題不夠具體，所以，這是最好的，我可以做的:)

DECLARE @client TABLE 
    (
     clientid int, 
     company VARCHAR(50) 
    ) 
    DECLARE @supportstatus TABLE 
    (
     clientid int, 
     [status] VARCHAR(50), 
     agreement INT 
    ) 

    INSERT INTO @client ([clientid],[company]) VALUES (0,'acme') 
    INSERT INTO @client ([clientid],[company]) VALUES (1,'byron') 
    INSERT INTO @client ([clientid],[company]) VALUES (2,'cathode') 

    INSERT INTO @supportstatus ([clientid],[status], agreement) VALUES (0, 'disabled',0) 
    INSERT INTO @supportstatus ([clientid],[status], agreement) VALUES (0, 'disabled',1) 
    INSERT INTO @supportstatus ([clientid],[status], agreement) VALUES (0, 'somethingelse',0) 
    INSERT INTO @supportstatus ([clientid],[status], agreement) VALUES (0, 'somethingelse',1) 

    INSERT INTO @supportstatus ([clientid],[status], agreement) VALUES (1, 'disabled',0) 
    INSERT INTO @supportstatus ([clientid],[status], agreement) VALUES (1, 'disabled',1) 
    --INSERT INTO @supportstatus ([clientid],[status], agreement) VALUES (1, 'somethingelse',0) 
    --INSERT INTO @supportstatus ([clientid],[status], agreement) VALUES (1, 'somethingelse',1) 

    --INSERT INTO @supportstatus ([clientid],[status], agreement) VALUES (2, 'disabled',0) 
    INSERT INTO @supportstatus ([clientid],[status], agreement) VALUES (2, 'disabled',1) 
    --INSERT INTO @supportstatus ([clientid],[status], agreement) VALUES (2, 'somethingelse',0) 
    INSERT INTO @supportstatus ([clientid],[status], agreement) VALUES (2, 'somethingelse',1) 

    -- all companies who have su.agreement = 0 and su.status <> 'disabled' 
    SELECT cl.company 
    FROM @client cl 
    JOIN @supportstatus su ON cl.clientid = su.clientid 
    WHERE su.agreement = 0 AND su.status <> 'disabled' 
    Order By cl.company