Question

添加几个连接后，当我进行连接时，我会得到重复项和其他数据。我可能做错了什么想法？

没有欺骗的旧代码：

SELECT
    dbo.dateonly(ctl.datetrans) AS DateRecorded, 
    L.Clientkey AS ClientNum, 
    L.Fullname, 
    cs.Datesvc, 
    cs.chargekey, 
    ctl.CheckNum, 
    ctl.ReceivedFrom, 
    ctl.Delta, 
    CONVERT(varchar(10), dept.deptkey) AS Deptkey, 
    dept.DeptName, 
    dept.PgmName, 
    CONVERT(varchar(10), dept.pgmKey) AS PGMKey, 
    ctl.Transtypelu
FROM
    bil_Chargetranslog ctl 
    LEFT JOIN dbo.BIL_ChargeSlips cs 
        ON cs.Chargekey = ctl.Chargekey 
    LEFT JOIN dbo.BLV_Clients L 
        ON cs.ClientKey = L.ClientKey 
    LEFT JOIN Blv_DeptPgm dept 
        ON dept.Pgmkey = cs.PgmLU
WHERE
    (
        ctl.Transtypelu = 4 
        AND (
            (
                ctl.descr <> 'Client Payment' 
                AND ctl.descr <> 'Copayment'
            ) OR ctl.descr IS NULL
        )
    )

UNION ALL

/* note below that the checknum is converted to a varchar for the query*/ 
SELECT 
    dbo.dateonly(daterecorded) AS daterecorded, 
    L.Clientkey AS ClientNum, 
    L.Fullname, 
    DatePayment, 
    NULL AS chargekey, 
    CONVERT(varchar(15), checknum) AS checknum, 
    NULL AS receivedfrom, 
    (- 1 * Amount) AS delta, 
    CONVERT(varchar(10), dept.deptkey) AS Deptkey, 
    dept.DeptName, 
    dept.PgmName, 
    CONVERT(varchar(10), dept.pgmKey) AS PGMKey, 
    4 AS transtypelu
FROM
    bil_clientdeposit 
    LEFT JOIN dbo.BLV_Clients L 
        ON bil_clientdeposit.ClientKey = L.ClientKey 
    LEFT JOIN Blv_DeptPgm dept 
        ON dept.Pgmkey = Bil_ClientDeposit.PgmKey

这是我的新代码：

SELECT
    dbo.dateonly(ctl.datetrans) AS DateRecorded, 
    L.Clientkey AS ClientNum, 
    L.Fullname, 
    cs.Datesvc, 
    cs.chargekey, 
    ctl.CheckNum, 
    ctl.ReceivedFrom, 
    ctl.Delta, 
    CONVERT(varchar(10), dept.deptkey) AS Deptkey, 
    dept.DeptName, 
    dept.PgmName, 
    CONVERT(varchar(10), dept.pgmKey) AS PGMKey, 
    ctl.Transtypelu, 
    pr.PlanName
FROM
    bil_Chargetranslog ctl 
    LEFT JOIN dbo.BIL_ChargeSlips cs 
        ON cs.Chargekey = ctl.Chargekey 
    LEFT JOIN dbo.BLV_Clients L 
        ON cs.ClientKey = L.ClientKey 
    LEFT JOIN Blv_DeptPgm dept 
        ON dept.Pgmkey = cs.PgmLU 
    left join BIL_ARTRANSLOG AR 
        ON ctl.chargekey = ar.chargekey 
    left join BIL_PAYORPLANS PR 
        ON PR.PAYORPLANKEY = AR.PAYORPLANKEY
WHERE
    (
        ctl.Transtypelu = 4 
        and ar.TransTypeLU = 4 
        AND (
            (
                ctl.descr <> 'Client Payment' 
                and AR.ARDescr <> 'Client Payment' 
                AND ctl.descr <> 'Copayment'
                and AR.ARDescr <> 'Copayment'
            ) OR ctl.descr IS NULL 
            or ar.ARDescr is null
        )
    )

UNION ALL

/* note below that the checknum is converted to a varchar for the query*/ 
SELECT  
    dbo.dateonly(daterecorded) AS daterecorded, 
    L.Clientkey AS ClientNum, 
    L.Fullname, 
    DatePayment, 
    NULL AS chargekey, 
    CONVERT(varchar(15), checknum) AS checknum, 
    NULL AS receivedfrom, 
    (- 1 * Amount) AS delta, 
    CONVERT(varchar(10), dept.deptkey) AS Deptkey, 
    dept.DeptName, 
    dept.PgmName, 
    CONVERT(varchar(10), dept.pgmKey) AS PGMKey, 
    4 AS transtypelu, 
    NULL as planname
FROM
    bil_clientdeposit 
    LEFT JOIN dbo.BLV_Clients L 
        ON bil_clientdeposit.ClientKey = L.ClientKey 
    LEFT JOIN Blv_DeptPgm dept 
        ON dept.Pgmkey = Bil_ClientDeposit.PgmKey

我添加了一行：

left join BIL_ARTRANSLOG AR 
    ON ctl.chargekey = ar.chargekey 
left join BIL_PAYORPLANS PR 
    ON PR.PAYORPLANKEY = AR.PAYORPLANKEY

Answer 1

“union”和“union all”之间的区别在于后者返回所有记录，而前者返回不同的记录。如果您不想要重复记录，请使用前者。

Answer 2

如果添加了一些额外的连接并且突然看到重复的行，则在一个或两个连接的表中可能存在一对多的关系，而这些关系在其他连接的表中不存在。尝试执行SELECT *，看看不同的列是什么似乎是重复记录。

您可以在SELECT语句前加上：

删除重复项

SELECT DISTINCT
    dbo.dateonly(ctl.datetrans) AS DateRecorded, 
    L.Clientkey AS ClientNum, 
    L.Fullname, 
    ....

在连接上添加行后获取重复项

2 个答案: