SQL查询以查找依赖于列值更改的最早日期

SELECt JobCodeId, MIN(LastEffectiveDate) AS mindate
FROM (
SELECt ,
prn - rn AS diff
FROM (
SELECt
,
ROW_NUMBER() OVER (PARTITION BY JobCodeID
ORDER BY LastEffectiveDate) AS prn,
ROW_NUMBER() OVER (ORDER BY LastEffectiveDate) AS rn
FROM @tmp
) q
) q2
GROUP BY
JobCodeId, diff
ORDER BY
mindate

连续范围在分区和未分区之间具有相同的区别

ROW_NUMBERs

您可以在中使用此值

GROUP BY