自我加入问题

Question

我有一个名为tblAccInfo的表,下面是表数据.我需要如下输出.

Input
PolicyNumber    BankAc   StorageDate    VerNum
6003210400      123      2012-01-01     1
6003210400      164      2012-01-03     2
6003210400      860      2012-01-05     3
6004317654      301      2012-02-05     1
6004317654      615      2012-03-01     2
6004317654      253      2012-03-12     3
6004317654      887      2012-04-03     4

OUTPUT

PolicyNumber  IntialBankAc IntialSDate VerNum  LatestBankAc LatestSDate VerNum
6003210400    123          2012-01-01  1       860          2012-01-05  3
6004317654    301          2012-02-05  1       887          2012-04-03  4

我试过下面的自我加入,但没有成功.请帮我解决这个问题.

Select DISTINCT
    P.PolicyNumber,
    P.BankAc [IntialBankAc],
    P.StorageDate IntialSDate],
    P.VerNum,
    P1.BankAc [LatestBankAc],
    P1.StorageDate [LatestSDate],
    P1.VerNum
FROM tblAccInfo P
INNER JOIN tblAccInfo P1
ON P1.PolicyNumber=P.PolicyNumber
AND (P.BankAc<>P1.BankAc AND P.StorageDate<>P1.StorageDate AND P.VerNum<>P1.VerNum)

Answer 1

尝试这个：

SELECT
    T1.PolicyNumber,
    T2.BankAc AS IntialBankAc,
    T2.StorageDate AS IntialSDate,
    T2.VerNum AS InitalVerNum,
    T3.BankAc AS LatestBankAc,
    T3.StorageDate AS LatestSDate,
    T3.Vernum AS LatestVerNum
FROM
(
    SELECT
        PolicyNumber,
        MIN(VerNum) AS MinVerNum,
        MAX(VerNum) AS MaxVerNum
    FROM tblAccInfo
    GROUP BY PolicyNumber
) AS T1
JOIN tblAccInfo AS T2
ON T1.PolicyNumber = T2.PolicyNumber
AND T1.MinVerNum = T2.VerNum
JOIN tblAccInfo AS T3
ON T1.PolicyNumber = T3.PolicyNumber
AND T1.MaxVerNum = T3.VerNum

查看它在线工作：sqlfiddle