日报数据统计中会用到当天数据的查询，下列就是日期要对应的条件：
between
to_date(to_char(sysdate,'yyyy-mm-dd') || ' 00:00:01','yyyy-mm-dd hh24:mi:ss') and
to_date(to_char(sysdate,'yyyy-mm-dd') || ' 23:59:59','yyyy-mm-dd hh24:mi:ss');
Oracle
字段类型为varchar2，格式要与格式化的样式匹配
当天select * from 表名 where to_char(to_date(字段名,'yyyy-mm-dd hh24:mi:ss'),'dd')=to_char(sysdate,'dd')当周select * from 表名 where to_char(to_date(字段名,'yyyy-mm-dd hh24:mi:ss'),'iw')=to_char(sysdate,'iw')当月select * from 表名 where to_char(to_date(字段名,'yyyy-mm-dd hh24:mi:ss'),'mm')=to_char(sysdate,'mm')当季度select * from 表名 where to_char(to_date(字段名,'yyyy-mm-dd hh24:mi:ss'),'q')=to_char(sysdate,'q')
字段类型为date
当天select * from 表名 where to_char(字段名,'dd')=to_char(sysdate,'dd')当周select * from 表名 where to_char(字段名,'iw')=to_char(sysdate,'iw')当月select * from 表名 where to_char(字段名,'mm')=to_char(sysdate,'mm')当季度select * from 表名 where to_char(字段名,'q')=to_char(sysdate,'q')
SQL
当天select * from 表名 where DATEPART(dd,字段名) = DATEPART(dd, GETDATE()) and DATEPART(mm, 字段名) = DATEPART(mm, GETDATE()) and DATEPART(yy, 字段名) = DATEPART(yy, GETDATE())当周select * from 表名 where DATEPART(wk, 字段名) = DATEPART(wk, GETDATE()) and DATEPART(yy, 字段名) = DATEPART(yy, GETDATE())当月select * from 表名 where DATEPART(mm, 字段名) = DATEPART(mm, GETDATE()) and DATEPART(yy, 字段名) = DATEPART(yy, GETDATE())当季度select * from 表名 where DATEPART(qq, 字段名) = DATEPART(qq, GETDATE()) and DATEPART(yy,字段名) = DATEPART(yy, GETDATE())
