同一个 table 上的多个连接？

Question

我有两个table:

tbl_EmploymentSegmentEM:

╔══════╦═════════════╦════════════╦═══════════════╦═══════════════════════════════╦════════════╦═════════════╦══════════════════════════╦════════════════╗
║ SrNo ║ CIBILTuefID ║ Prospectno ║ ApplicantType ║         ApplicantName         ║ SegmentTag ║ AccountType ║ DateReportedandCertified ║ OccupationCode ║
╠══════╬═════════════╬════════════╬═══════════════╬═══════════════════════════════╬════════════╬═════════════╬══════════════════════════╬════════════════╣
║    1 ║           1 ║     718580 ║ APPLICANT     ║ RAJKUMAR GIRISHCHANDRA PANDEY ║ E01        ║          10 ║                 31122014 ║             02 ║
║    2 ║           4 ║     718638 ║ APPLICANT     ║ Anil Kumar Aggarwal           ║ E01        ║          10 ║                 31122014 ║             01 ║
╚══════╩═════════════╩════════════╩═══════════════╩═══════════════════════════════╩════════════╩═════════════╩══════════════════════════╩════════════════╝

tbl_CIBILFieldDescription:

╔════════╦══════════╦══════════════════════════════╦═══════╦═════════════════════════════╗
║ Header ║ FieldTag ║          FieldName           ║ Value ║      ValueDescription       ║
╠════════╬══════════╬══════════════════════════════╬═══════╬═════════════════════════════╣
║ PT     ║       03 ║ TelephoneType                ║ 03    ║ Office Phone                ║
║ EM     ║       03 ║ OccupationCode               ║ 01    ║ Salaried                    ║
║ EM     ║       03 ║ OccupationCode               ║ 02    ║ Self Employed Professional. ║
║ EM     ║       03 ║ OccupationCode               ║ 03    ║ Self Employed               ║
║ EM     ║       03 ║ OccupationCode               ║ 04    ║ Others                      ║
║ EM     ║       05 ║ NetGrossIncomeIndicator      ║ G     ║ Gross Income                ║
║ EM     ║       05 ║ NetGrossIncomeIndicator      ║ N     ║ Net Income                  ║
║ EM     ║       06 ║ MonthlyAnnualIncomeIndicator ║ M     ║ Net Monthly                 ║
║ EM     ║       06 ║ MonthlyAnnualIncomeIndicator ║ A     ║ Net Annual                  ║
║ SC     ║       01 ║ ScoreCardName                ║ 01    ║ CIBILTUSCR                  ║
╚════════╩══════════╩══════════════════════════════╩═══════╩═════════════════════════════╝

我正在尝试从 tbl_CIBILFieldDescription 中获取相应值的帐户类型和职业代码描述。

我试过了：

SELECT DISTINCT CIBILTuefID, 
                Prospectno, 
                ApplicantType, 
                ApplicantName, 
                SegmentTag, 
                AccountType, 
                DateReportedandCertified, 
                OccupationCode, 
                mst.ValueDescription  AS OccupationCodeDesc, 
                Income, 
                NetGrossIncomeIndicator, 
                mst.ValueDescription AS NetGrossIncomeIndicatorDesc, 
                MonthlyAnnualIncomeIndicator, 
                DateofEntryforErrorCode, 
                ErrorCode, 
                DateofEntryforCIBILRemarksCode, 
                CIBILRemarksCode, 
                DateofEntryforErrorDisputeRemarksCode, 
                ErrorDisputeRemarksCode1, 
                ErrorDisputeRemarksCode2, 
                MkrId, 
                MkdDt 
FROM   tbl_EmploymentSegmentEM EM 
INNER JOIN tbl_CIBILFieldDescription mst 
    ON 1 = 1 
WHERE mst.Header = 'EM' 
  AND mst.FieldName = 'OccupationCode' 
  AND mst.Value = EM.OccupationCode

它似乎对 OccupationCode 工作正常，但如果我想从同一个查询中同时获得 OccupationCode 和 AccountType 怎么办？做这个的最好方式是什么？

Answer 1

您可以使用 LEFT JOIN:

多次加入您的 table

SELECT DISTINCT cibiltuefid, 
                prospectno, 
                applicanttype, 
                applicantname, 
                segmenttag, 
                accounttype, 
                datereportedandcertified, 
                occupationcode, 
                mst.valuedescription  AS OccupationCodeDesc, 
                income, 
                netgrossincomeindicator, 
                mst1.valuedescription AS NetGrossIncomeIndicatorDesc, 
                monthlyannualincomeindicator, 
                dateofentryforerrorcode, 
                errorcode, 
                dateofentryforcibilremarkscode, 
                cibilremarkscode, 
                dateofentryforerrordisputeremarkscode, 
                errordisputeremarkscode1, 
                errordisputeremarkscode2, 
                mkrid, 
                mkddt 
                ,mst.ValueDescription AS Occupation
                ,mst1.ValueDescription AS Account
FROM tbl_employmentsegmentem EM
LEFT JOIN tbl_cibilfielddescription mst 
    ON mst.fieldname = 'OccupationCode' 
    AND mst.value = EM.occupationcode 
    AND mst.header = 'EM'
LEFT JOIN tbl_cibilfielddescription mst1 
    ON mst1.fieldname = 'AccountType' 
    AND mst1.value = EM.accounttype
    AND mst1.header = 'EM'

同一个 table 上的多个连接？

Multiple joins on same table?

sql

sql-server

join

sql-server-2005