qq_43002000的博客

--错误SELECT DISTINCT ip, CONVERT(nvarchar(12),datetime,112) AS aa FROM EMH_log_access WHERE datetime > '2019-11-01' group by aaORDER BY aa desc--正确SELECT count(DISTINCT ip), CONVERT(nvarcha...

今天的所有数据：select * from 表名 where DateDiff(dd,datetime类型字段,getdate())=0昨天的所有数据：select * from 表名 where DateDiff(dd,datetime类型字段,getdate())=17天内的所有数据：select * from 表名 where DateDiff(dd,datetime类型字段,getda...

SELECT A.* FROM **表1** A LEFT JOIN ( SELECT 字段一 ,max(**时间**) time FROM **表一** GROUP BY 字段一 ) B on A.字段一 = B.字段一 WHERE A.time = B.time

if exists(select seq from 表) begin 执行 第一个sql end else begin 执行第二个sql end