untuk SQL Server 2005 dan lebih tinggi coba:
;WITH SalesScore AS (
SELECT
s.PK_ID as S_PK
,c.PK_ID AS c_PK
,CASE
WHEN c.PK_ID IS NULL THEN 0
ELSE CASE WHEN s.ServiceId=c.ServiceId THEN 1 ELSE 0 END
+CASE WHEN (s.Address=c.Address AND s.Zip=c.Zip) THEN 1 ELSE 0 END
+CASE WHEN s.EmailAddress=c.EmailAddress THEN 1 ELSE 0 END
+CASE WHEN s.HomePhone=c.HomePhone THEN 1 ELSE 0 END
END AS Score
FROM Sales s
LEFT OUTER JOIN Customers c ON s.ServiceId=c.ServiceId
OR (s.Address=c.Address AND s.Zip=c.Zip)
OR s.EmailAddress=c.EmailAddress
OR s.HomePhone=c.HomePhone
)
SELECT
s.*,c.*
FROM (SELECT
S_PK,MAX(Score) AS Score
FROM SalesScore
GROUP BY S_PK
) dt
INNER JOIN Sales s ON dt.s_PK=s.PK_ID
INNER JOIN SalesScore ss ON dt.s_PK=s.PK_ID AND dt.Score=ss.Score
LEFT OUTER JOIN Customers c ON ss.c_PK=c.PK_ID
EDIT Saya benci menulis begitu banyak kode aktual ketika tidak ada shema yang diberikan, karena saya tidak dapat benar-benar menjalankan ini dan memastikan itu berfungsi. Namun untuk menjawab pertanyaan tentang cara menangani ikatan menggunakan tanggal transaksi terakhir, berikut adalah versi terbaru dari kode di atas:
;WITH SalesScore AS (
SELECT
s.PK_ID as S_PK
,c.PK_ID AS c_PK
,CASE
WHEN c.PK_ID IS NULL THEN 0
ELSE CASE WHEN s.ServiceId=c.ServiceId THEN 1 ELSE 0 END
+CASE WHEN (s.Address=c.Address AND s.Zip=c.Zip) THEN 1 ELSE 0 END
+CASE WHEN s.EmailAddress=c.EmailAddress THEN 1 ELSE 0 END
+CASE WHEN s.HomePhone=c.HomePhone THEN 1 ELSE 0 END
END AS Score
FROM Sales s
LEFT OUTER JOIN Customers c ON s.ServiceId=c.ServiceId
OR (s.Address=c.Address AND s.Zip=c.Zip)
OR s.EmailAddress=c.EmailAddress
OR s.HomePhone=c.HomePhone
)
SELECT
*
FROM (SELECT
s.*,c.*,row_number() over(partition by s.PK_ID order by s.PK_ID ASC,c.LastTransaction DESC) AS RankValue
FROM (SELECT
S_PK,MAX(Score) AS Score
FROM SalesScore
GROUP BY S_PK
) dt
INNER JOIN Sales s ON dt.s_PK=s.PK_ID
INNER JOIN SalesScore ss ON dt.s_PK=s.PK_ID AND dt.Score=ss.Score
LEFT OUTER JOIN Customers c ON ss.c_PK=c.PK_ID
) dt2
WHERE dt2.RankValue=1