看看以前的私密日志，原来自己之前被很多小而简单的问题困惑过！
看着那时候我们还是新手中的新手做的备忘笔记！
其实就是用了Oracle的统计函数而已！
以前的日记（看样子应该是以前公司的源码，呵呵……）如下：勿喷！
对多数据进行分组排序后取每组第一条记录：
SELECT * FROM ( SELECT ROW_NUMBER() OVER( PARTITION BY ZA40011_3.URIAGE_DENPYO_NO,ZA40011_3.URIAGE_DENPYO_ROW_NO ORDER BY ZA40011_3.KAKUTEI_SURYO_CS, ZA40011_3.KAKUTEI_SURYO_BL, ZA40011_3.KAKUTEI_SURYO_BT, ZA40011_3.SYUKKA_SHIJI_NO, ZA40011_3.SYUKKA_SHIJI_ROW_NO DESC) LEV, ZA40011_3 .* FROM WT_001_ZA40011_22070_2 ZA40011_2, WT_001_ZA40011_22070_3 ZA40011_3, JT_GYOMU_URIAGE_DETAIL URIAGE_DETAIL WHERE ZA40011_2.KAISYA_CODE = URIAGE_DETAIL.KAISYA_CODE AND ZA40011_2.URIAGE_DENPYO_NO = URIAGEoracle账号_DETAIL.URIAGE_DENPYO_NO AND ZA40011_2.URIAGE_DENPYO_ROW_NO = URIAGE_DETAIL.ROW_NO AND URIAGE_DETAIL.KAISYA_CODE = ZA40011_3.KAISYA_CODE AND URIAGE_DETAIL.URIAGE_DENPYO_NO = ZA40011_3.URIAGE_DENPYO_NO AND URIAGE_DETAIL.ROW_NO = ZA40011_3.URIAGE_DENPYO_ROW_NO AND ZA40011_3.KEPPIN_RIYU_CODE IS NOT NULL ) WHERE LEV = 1-- ORDER BY KAKUTEI_SURYO_CS DESC