在表中,可能会包含重复值。这并不成问题,不过,有时您也许希望仅仅列出不同(distinct)的值。关键词 distinct用于返回唯一不同的值。表A:示例1复制代码 代码如下:select distinct name from A执行后结果如下:示例2select distinct name, id fr..
我就废话不多说了,大家还是直接看代码吧~select count(s.*)from (select *, row_number() over (partition by fee_date order by fee_date) as grfrom new_order where news_id='novel' and order_status='2' ) swhere s.gr = 1 SELECT count(DIST..
比如现在有一人员表 (表名:peosons)若想将姓名、身份证号、住址这三个字段完全相同的记录查询出来 复制代码 代码如下:select p1.* from persons p1,persons p2 where p1.id<>p2.id and p1.cardid = p2.cardid and p1.pname = p2.pname and p1.ad..