使用没有重复结果的 case 和 like 语句

Question

我正在尝试使用 case 和 like 语句。当我运行以下查询时，它在某些行上复制结果，而在特定列上它是 y 。我正在使用 SQL Server 2000。

SELECT DISTINCT [rjvn_pound_reference]
    ,t_reference
    ,t_street_name
    ,t_zone_name
    ,(
        CASE 
            WHEN rjvn_note LIKE '%CORRESPONDENCE%'
                THEN 'Y'
            ELSE 'N'
            END
        ) AS CorrespondenceReceived
    ,(
        CASE 
            WHEN rjvn_note LIKE '%review form complete%'
                THEN 'Y'
            ELSE 'N'
            END
        ) AS REVIEWFORMCOMPLETE
    ,(
        CASE 
            WHEN rjvn_note LIKE '%Manually issued NTO - Drive off%'
                THEN 'Y'
            ELSE 'N'
            END
        ) AS ManuallyissuedNTO
    ,(
        CASE 
            WHEN rjvn_note LIKE '%Manually issued NTK - Drive Off%'
                THEN 'Y'
            ELSE 'N'
            END
        ) AS ManuallyissuedNTK
    ,(
        CASE 
            WHEN rjvn_note LIKE '%Drive off- Final reminder sent%'
                THEN 'Y'
            ELSE 'N'
            END
        ) AS finalReminderSent
FROM [ICPS].[dbo].[removal_job_vehicle_notes] AS a
INNER JOIN tickets t ON (a.rjvn_pound_reference = t.t_number)
INNER JOIN dbo.ticket_hold_record thr ON (t.t_number = thr.thr_system_ref)
WHERE thr_hold_type = '2207555'
    AND t.t_contract IN ('18','1')

结果：

805464  XL05512211  Selby (60-100)  Abbey Walk  N   N   Y   N   N
805464  XL05512211  Selby (60-100)  Abbey Walk  N   Y   N   N   N
805464  XL05512211  Selby (60-100)  Abbey Walk  Y   N   N   N   N

但我希望它显示在单行上，而不是像：

805464  XL05512211  Selby (60-100)  Abbey Walk  Y   Y   Y   N   N.

UPDATED :
944786  XL07075730  Selby (60-100)  Abbey Walk  N   N   N   N   Y   
but I should get
944786  XL07075730  Selby (60-100)  Abbey Walk  N   N   Y   N   Y

我的实际 TABLE 该记录的数据：

rjvn_pound_reference    rjvn_time                 rjvn_userid      rjvn_note
944786                  2014-01-08 10:38:17.000   JAMIED           Vehicle Drove Away During PCN Issue
944786                  2014-01-08 14:22:21.000   ADRIANJ          Correspondent Scanned
944786                  2014-02-05 15:44:53.000   ELLIED           Manually issued NTO drive off
944786                  2015-03-12 10:16:53.000   KATIEB           Drive off- Final reminder sent

--manually issued NTO drive off is displayed as 'N' instead of 'y'

Answer 1

试试这个：

SELECT [RJVN_POUND_REFERENCE],
  T_REFERENCE,
  T_STREET_NAME,
  T_ZONE_NAME,
  DECODE(MAX(CASE WHEN RJVN_NOTE LIKE '%CORRESPONDENCE%' THEN 1 ELSE 0 END), 1, 'Y', 'N') AS CORRESPONDENCERECEIVED,
  DECODE(MAX(CASE WHEN RJVN_NOTE LIKE '%review form complete%' THEN 1 ELSE 0 END), 1, 'Y', 'N') AS REVIEWFORMCOMPLETE,
  DECODE(MAX(CASE WHEN RJVN_NOTE LIKE '%Manually issued NTO - Drive off%' THEN 1 ELSE 0 END), 1, 'Y', 'N') AS MANUALLYISSUEDNTO,
  DECODE(MAX(CASE WHEN RJVN_NOTE LIKE '%Manually issued NTK - Drive Off%' THEN 1 ELSE 0 END), 1, 'Y', 'N') AS MANUALLYISSUEDNTK,
  DECODE(MAX(CASE WHEN RJVN_NOTE LIKE '%Drive off- Final reminder sent%' THEN 1 ELSE 0 END), 1, 'Y', 'N') AS FINALREMINDERSENT
FROM [ICPS].[DBO].[REMOVAL_JOB_VEHICLE_NOTES] AS A
INNER JOIN TICKETS T
ON(A.RJVN_POUND_REFERENCE=T.T_NUMBER)
INNER JOIN DBO.TICKET_HOLD_RECORD THR
ON(T.T_NUMBER=THR.THR_SYSTEM_REF)
WHERE THR_HOLD_TYPE='2207555'
  AND T.T_CONTRACT IN('18', '1')
GROUP BY [RJVN_POUND_REFERENCE],
  T_REFERENCE,
  T_STREET_NAME,
  T_ZONE_NAME

Answer 2

在您的案例陈述中使用 Max 并按照@jarlh 的建议进行分组应该适合您：

SELECT q1.[rjvn_pound_reference]
    ,q1.t_reference
    ,q1.t_street_name
    ,q1.t_zone_name
    ,(
        CASE 
            WHEN q1.CorrespondenceReceived = 1
                THEN 'Y'
            ELSE 'N'
            END
        ) CorrespondenceReceived
    ,(
        CASE 
            WHEN q1.REVIEWFORMCOMPLETE = 1
                THEN 'Y'
            ELSE 'N'
            END
        ) REVIEWFORMCOMPLETE
    ,(
        CASE 
            WHEN q1.ManuallyissuedNTO = 1
                THEN 'Y'
            ELSE 'N'
            END
        ) ManuallyissuedNTO
    ,(
        CASE 
            WHEN q1.ManuallyissuedNTK = 1
                THEN 'Y'
            ELSE 'N'
            END
        ) ManuallyissuedNTK
    ,(
        CASE 
            WHEN q1.finalReminderSent = 1
                THEN 'Y'
            ELSE 'N'
            END
        ) finalReminderSent
FROM (
    SELECT [rjvn_pound_reference]
        ,t_reference
        ,t_street_name
        ,t_zone_name
        ,MAX(CASE 
                WHEN rjvn_note LIKE '%CORRESPONDENCE%'
                    THEN 1
                ELSE 0
                END) AS CorrespondenceReceived
        ,MAX(CASE 
                WHEN rjvn_note LIKE '%review form complete%'
                    THEN 1
                ELSE 0
                END) AS REVIEWFORMCOMPLETE
        ,MAX(CASE 
                WHEN rjvn_note LIKE '%Manually issued NTO - Drive off%'
                    THEN 1
                ELSE 0
                END) AS ManuallyissuedNTO
        ,MAX(CASE 
                WHEN rjvn_note LIKE '%Manually issued NTK - Drive Off%'
                    THEN 1
                ELSE 0
                END) AS ManuallyissuedNTK
        ,MAX(CASE 
                WHEN rjvn_note LIKE '%Drive off- Final reminder sent%'
                    THEN 1
                ELSE 0
                END) AS finalReminderSent
    FROM [ICPS].[dbo].[removal_job_vehicle_notes] AS a
    INNER JOIN tickets t ON (a.rjvn_pound_reference = t.t_number)
    INNER JOIN dbo.ticket_hold_record thr ON (t.t_number = thr.thr_system_ref)
    WHERE thr_hold_type = '2207555'
        AND t.t_contract IN (
            '18'
            ,'1'
            )
    GROUP BY [rjvn_pound_reference]
        ,t_reference
        ,t_street_name
        ,t_zone_name
    ) q1

Answer 3

因为查询中的列引用不合格（指示它们是从哪个 table返回的），并且因为我们没有模式定义通过整理...我们无法判断 table rjvn_note 列的来源。

就获得 "duplicate" 行而言，最可能的解释是 JOIN，存在一对多关联，并且返回多行。这是预期的行为。

至"collapse"行，您可以在查询末尾添加GROUP BY。您还可以使用聚合函数（如 MIN() 或 MAX()）到 "pick out" 表达式返回的值来自折叠的行。

DISTINCT 关键字（在您的查询中）作用于 [=72] 中的整个表达式集=] 列表。这将消除完全重复的行。

在某些情况下，还有其他一些有用的替代方法。例如，用作 EXISTS 谓词（它的要求是测试相关 table 中是否存在一行，而不产生 "duplicates"就像 JOIN 操作一样。或者，在 SELECT 列表中使用子查询。

因为列引用不合格，而且因为我们没有模式定义，所以我们真的只是猜测。有些 "maybe try this" 猜测可能是正确的，但它们只是猜测。

这是我的"guess"，您需要对查询进行更改以获得指定的结果集：

放弃 DISTINCT 关键字
在 CASE 表达式周围添加 MAX() 聚合
添加一个 GROUP BY 子句，列出 SELECT 列表中的所有非聚合表达式
（可选）用 table 别名限定所有列引用（这样做的几个很好的理由：作为对未来读者的帮助，并使语句免受未来失败的影响

SELECT a.rjvn_pound_reference
     , t.t_reference
     , t.t_street_name
     , t.t_zone_name
     , MAX(CASE WHEN a.rjvn_note LIKE   '%CORRESPONDENCE%'
                THEN 'Y' ELSE 'N' END
       ) AS CorrespondenceReceived
     , MAX(CASE WHEN a.rjvn_note LIKE   '%review form complete%'
                THEN 'Y' ELSE 'N' END
       ) AS REVIEWFORMCOMPLETE
     , MAX(CASE WHEN a.rjvn_note LIKE   '%Manually issued NTO - Drive off%'
                THEN 'Y' ELSE 'N' END
       ) AS ManuallyissuedNTO
     , MAX(CASE WHEN a.rjvn_note LIKE   '%Manually issued NTK - Drive Off%'
                THEN 'Y' ELSE 'N'END
       ) AS ManuallyissuedNTK
     , MAX(CASE WHEN a.rjvn_note LIKE   '%Drive off- Final reminder sent%'
                THEN 'Y' ELSE 'N' END
       ) AS finalReminderSent
  FROM [ICPS].[dbo].[removal_job_vehicle_notes] a
  JOIN [tickets] t
    ON t.t_number = a.rjvn_pound_reference
  JOIN [dbo].[ticket_hold_record] thr 
    ON thr_system_ref = t.t_number
 WHERE thr.thr_hold_type = '2207555'
   AND t.t_contract IN ('18','1')
 GROUP
    BY a.rjvn_pound_reference
     , t.t_reference
     , t.t_street_name
     , t.t_zone_name

使用没有重复结果的 case 和 like 语句

Using case and like statment without duplicate results

sql

sql-server

sql-server-2000