标签：CONVERT DATEPART varchar 函数 current birthday PG SQL date

POSTGRESQL日期函数大全

 一：各个数据中的连接符

SqlServer的连接符：+（加号）

Sqlite的连接符：.（点）

PostgreSQL的连接符：||（或）

二：

PostgreSQL部分的日期函数及变量

to_char()、Date()、now()、current_date

计算两个日期的差

current_date为今天的日期，为：2015-06-03

Date('2015-06-05')-current_date=2

select   to_char(current_date,'yyyy')||'-'||to_char(birthday,'mm-dd'),Date(to_char(current_date,'yyyy')||'-'||to_char(birthday,'mm-dd'))-current_date 

from tablename where delflag=0 and status=0 

and Date(to_char(current_date,'yyyy')||'-'||to_char(birthday,'mm-dd'))-current_date>=0 

and Date(to_char(current_date,'yyyy')||'-'||to_char(birthday,'mm-dd'))-current_date<=7
order by birthday desc

三：

select now() + interval '1 days'; 

select now() + interval '1 month'; 

select now() + interval '1 years'; 

四：

SqlServer中进行日期计算时，用到函数

CONVERT（）,DATEPART(),getDate()

select CONVERT(varchar(10),CONVERT(varchar(4),DATEPART(year,getDate()))+'-'+ CONVERT(varchar(2),DATEPART(month,birthday))+'-'+CONVERT(varchar(2),DATEPART(day,birthday)),120),datediff(day,CONVERT(varchar(10),getdate(),120),CONVERT(varchar(10),CONVERT(varchar(4),DATEPART(year,getDate()))+'-'+ CONVERT(varchar(2),DATEPART(month,birthday))+'-'+CONVERT(varchar(2),DATEPART(day,birthday)),120)) 

from tablename where delflag=0 and status=0 

and datediff(day,CONVERT(varchar(10),getdate(),120),CONVERT(varchar(10),CONVERT(varchar(4),DATEPART(year,getDate()))+'-'+ CONVERT(varchar(2),DATEPART(month,birthday))+'-'+CONVERT(varchar(2),DATEPART(day,birthday)),120))<=7 

and datediff(day,CONVERT(varchar(10),getdate(),120),CONVERT(varchar(10),CONVERT(varchar(4),DATEPART(year,getDate()))+'-'+ CONVERT(varchar(2),DATEPART(month,birthday))+'-'+CONVERT(varchar(2),DATEPART(day,birthday)),120))>=0 order by birthday desc

 

标签：CONVERT,DATEPART,varchar,函数,current,birthday,PG,SQL,date
From： https://www.cnblogs.com/cherxu204/p/17029831.html