Question

我有一个使用JOIN编写的查询，使用部件的Serial_Number显示摘要。

显然，它不起作用！

在此处使用直接搜索：

select Serial_Number, Op_ID, Date_Time as 'DecayDate', 
    DECAY.System_ID AS 'DecayID', Test_Result as 'DecayResult' 
from Test_Results
where serial_number='CP21295 1006 09' and system_id like '%decay%'

我得到了这个示例输出：

Serial_Number     Op_ID   DecayDate               DecayID      DecayResult
CP21295 1006 09   003468  2009-10-15 06:36:13.643 AA_DECAY_6   FAILED
CP21295 1006 09   003468  2009-10-05 08:08:38.503 AA_DECAY_6   PASSED

请注意，对于这个需要结果的部件号，有两（2）次测试。

现在我创建的查询不起作用：

第一个版本将返回 ONE 记录：

SELECT LABEL.Serial_Number, 
  DECAY.Op_ID,
  DECAY.Date_Time AS 'DecayDate',
  DECAY.System_ID AS 'DecayID',
  CASE
    WHEN DECAY.Test_Result LIKE '%fail%' THEN 'FAIL'
    WHEN DECAY.Test_Result LIKE '%pass%' THEN 'PASS'
    ELSE NULL
  END AS 'DecayResult'
  FROM 
  ACP_Parts AS LABEL
  LEFT OUTER JOIN (
    SELECT I.Serial_Number, I.Op_ID, I.Date_Time, I.System_ID, I.Test_Result
        FROM Test_Results I
    LEFT OUTER JOIN Test_Results O ON (
        I.Serial_Number=O.Serial_Number) AND 
        (O.Date_Time<I.Date_Time) -- AND (O.Serial_Number IS NULL) // didn't work
    WHERE
        (I.Test_Result LIKE '%pass%' OR I.Test_Result LIKE '%fail%') AND 
        (I.System_ID like '%decay%') AND
        (O.Test_Result LIKE '%pass%' OR O.Test_Result LIKE '%fail%') AND
        (O.System_ID like '%decay%')
    ) AS DECAY ON 
        (LABEL.Serial_Number=DECAY.Serial_Number) AND 
        (LABEL.Date_Time<DECAY.Date_Time)
  WHERE 
    (LABEL.Serial_Number IN (
        SELECT DISTINCT Serial_Number 
        FROM ACP_Parts 
        WHERE (Serial_Number IS NOT NULL) AND 
         (DATEADD(yy, - 1, GETDATE()) < Date_Time)))

输出

Serial_Number     DecayOp DecayDate               DecayID              DecayResult
CP21295 1006 09   003468  2009-10-15 06:36:13.643 AA_DECAY_6           PASS

我猜测上面的查询产生了一个结果，因为它有两个或多个记录可供比较。正确？

我修改了上面的查询，希望返回最新的记录，但是这个版本没有返回任何内容：

SELECT LABEL.Serial_Number, 
  DECAY.Op_ID,
  DECAY.Date_Time AS 'DecayDate',
  DECAY.System_ID 'DecayID',
  CASE
    WHEN DECAY.Test_Result LIKE '%fail%' THEN 'FAIL'
    WHEN DECAY.Test_Result LIKE '%pass%' THEN 'PASS'
    ELSE NULL
  END AS 'DecayResult'
  FROM 
  ACP_Parts AS LABEL
  LEFT OUTER JOIN (
    SELECT TOP 1 Serial_Number, Op_ID, Date_Time, System_ID, Test_Result
    FROM Test_Results
    WHERE
      (System_ID like '%decay%') AND
      (Test_Result LIKE '%pass%' OR Test_Result LIKE '%fail%')
    ORDER BY Date_Time DESC
    ) AS DECAY ON 
        (LABEL.Serial_Number=DECAY.Serial_Number) AND 
        (LABEL.Date_Time<DECAY.Date_Time)
  WHERE 
    (LABEL.Serial_Number IN (
        SELECT DISTINCT Serial_Number 
        FROM ACP_Parts 
        WHERE (Serial_Number IS NOT NULL) AND 
         (DATEADD(yy, - 1, GETDATE()) < Date_Time)))

输出

Serial_Number     DecayOp DecayDate               DecayID              DecayResult
CP21295 1006 09   NULL    NULL                    NULL                 NULL

有人可以指出我如何能够让这个查询返回我之后的单个结果吗？

Answer 1

我认为你想要每个部分的最新test_result记录是对的吗？

在MSDN文档中查看ROW_NUMBER() OVER (PARTITION BY... ORDER BY ...) - 假设您正在使用MSSQL 2005或更高版本，这将使它变得非常简单。

Answer 2

好的，我已经找到了调整代码的方法来产生我想要的结果。

首先，这是我使用的数据：

CREATE TABLE JP1 (Serial_Number VarChar(20), Date_Time DateTime, Test_Result VarChar(255))
INSERT JP1 VALUES ('T900 09', '2009-10-10 01:15:00.000', 'NO TEST, Failed to Dump')
INSERT JP1 VALUES ('T901 09', '2009-10-10 01:20:00.000', '(BLUE) PASS (WHITE) FAIL')

CREATE TABLE JP2 (Serial_Number VarChar(20), Date_Time DateTime, Test_Result VarChar(255))
INSERT JP2 VALUES ('T900 09', '2009-10-15 01:15:00.000', 'NO TEST, Failed to Dump')
INSERT JP2 VALUES ('T900 09', '2009-10-15 02:15:00.000', '(BLUE) PASS (WHITE) FAIL')
INSERT JP2 VALUES ('T900 09', '2009-10-15 04:25:00.000', 'TEST ABORTED')
INSERT JP2 VALUES ('T900 09', '2009-10-15 04:59:00.000', '(BLUE) FAIL (WHITE) FAIL')
INSERT JP2 VALUES ('T900 09', '2009-10-15 05:09:00.000', '(WHITE) NO TEST')
INSERT JP2 VALUES ('T900 09', '2009-10-15 05:34:00.000', 'B=Pass.,W=FAIL, Final Fill')
INSERT JP2 VALUES ('T900 09', '2009-10-15 06:06:00.000', 'PASSED PD')
INSERT JP2 VALUES ('T900 09', '2009-10-15 06:30:00.000', 'TEST ABORTED')
INSERT JP2 VALUES ('T900 09', '2009-10-15 06:36:00.000', 'PASS')
INSERT JP2 VALUES ('T900 09', '2009-10-15 06:50:00.000', 'FAIL')
INSERT JP2 VALUES ('T900 09', '2009-10-05 08:08:00.000', 'NO TEST, Operator cancel')

接下来，我创建了两（2）个非常相似的查询。事实证明，我需要在LEFT OUTER JOIN子句中模仿我在WHERE子句中提出的要求。

以下是我如何提取 FIRST PASS结果和日期：

SELECT LABEL.Serial_Number, 
    DECAY.Date_Time AS 'DecayDate',
    CASE
    WHEN DECAY.Test_Result LIKE '%fail%' THEN 'FAIL'
    WHEN DECAY.Test_Result LIKE '%pass%' THEN 'PASS'
    ELSE NULL
    END AS 'DecayResult'
FROM JP1 AS LABEL
LEFT OUTER JOIN (
    SELECT I.Serial_Number, I.Date_Time, I.Test_Result
    FROM
        JP2 AS I
        LEFT OUTER JOIN JP2 AS O
        ON
        (I.Serial_Number=O.Serial_Number) AND
        ((O.Test_Result LIKE '%pass%') OR (O.Test_Result LIKE '%fail%')) AND -- //Gets First Test!
        (O.Test_Result NOT LIKE '%NO TEST%') AND
        (O.Date_Time<I.Date_Time) -- //(selects FIRST pass or fail)
        -- (I.Date_Time<O.Date_Time) -- //(selects LAST pass or fail)
    WHERE
        (I.Test_Result LIKE '%pass%' OR I.Test_Result LIKE '%fail%') AND -- //Gets First Test!
        (I.Test_Result NOT LIKE '%NO TEST%') AND
        (O.Serial_Number IS NULL)
) AS DECAY ON 
(LABEL.Serial_Number=DECAY.Serial_Number) AND 
(LABEL.Date_Time<DECAY.Date_Time)
WHERE 
(LABEL.Serial_Number IN (
    SELECT DISTINCT Serial_Number 
    FROM JP1
    WHERE (Serial_Number IS NOT NULL) AND 
    (DATEADD(yy, - 1, GETDATE()) < Date_Time))
)

以下是我如何提取 FIRST 测试结果和日期：

SELECT LABEL.Serial_Number, 
    DECAY.Date_Time AS 'DecayDate',
    CASE
    WHEN DECAY.Test_Result LIKE '%fail%' THEN 'FAIL'
    WHEN DECAY.Test_Result LIKE '%pass%' THEN 'PASS'
    ELSE NULL
    END AS 'DecayResult'
FROM JP1 AS LABEL
LEFT OUTER JOIN (
    SELECT I.Serial_Number, I.Date_Time, I.Test_Result
    FROM
        JP2 AS I
        LEFT OUTER JOIN JP2 AS O
        ON
        (I.Serial_Number=O.Serial_Number) AND
        ((O.Test_Result LIKE '%pass%') AND (O.Test_Result NOT LIKE '%fail%')) AND -- //Gets First Pass!
        (O.Test_Result NOT LIKE '%NO TEST%') AND
        (O.Date_Time<I.Date_Time) -- //(selects FIRST pass or fail)
        -- (I.Date_Time<O.Date_Time) -- //(selects LAST pass or fail)
    WHERE
        (I.Test_Result LIKE '%pass%' AND I.Test_Result NOT LIKE '%fail%') AND -- //Gets First Pass!
        (I.Test_Result NOT LIKE '%NO TEST%') AND
        (O.Serial_Number IS NULL)
) AS DECAY ON 
(LABEL.Serial_Number=DECAY.Serial_Number) AND 
(LABEL.Date_Time<DECAY.Date_Time)
WHERE 
(LABEL.Serial_Number IN (
    SELECT DISTINCT Serial_Number 
    FROM JP1
    WHERE (Serial_Number IS NOT NULL) AND 
    (DATEADD(yy, - 1, GETDATE()) < Date_Time))
)

我希望其他人觉得这很有用！

〜乔

T-SQL外部联接不起作用

2 个答案: