SQL 如何获取代表一个月第一天的日期？
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How to get date representing the first day of a month?
提问by DaveDev
I need functionality in a script that will enable me to insert dates into a table.
我需要脚本中的功能，使我能够将日期插入表中。
What SQL do I need to insert a date of the format
我需要什么 SQL 来插入格式的日期
01/08/2010 00:00:00
where the date is the first day of the current month. What do I need to change order that I can specify the month value? Thanks
其中日期是当月的第一天。我需要更改什么才能指定月份值？谢谢
回答by Icemanind
The best and easiest way to do this is to use:
最好和最简单的方法是使用：
SELECT DATEADD(m, DATEDIFF(m, 0, GETDATE()), 0)
Just replace GETDATE() with whatever date you need.
只需将 GETDATE() 替换为您需要的任何日期。
回答by jmoreno
The accepted answer works, and may be faster, but SQL 2012 and above have a more easily understood method:
接受的答案有效，并且可能更快，但 SQL 2012 及更高版本有一个更容易理解的方法：
SELECT cast(format(GETDATE(), 'yyyy-MM-01') as Date)
回答by Joe Stefanelli
select cast(cast(datepart(year,getdate()) as char(4))
+ '/'
+ cast(datepart(month,getdate()) as char(2))
+ '/01' as datetime)
回答by iliketocode
Here is a very simple way to do this (using SQL 2012 or later)
这是一个非常简单的方法（使用 SQL 2012 或更高版本）
datefromparts(year(getdate()),month(getdate()),1)
you can also easily get the last day of the month using
您还可以使用
eomonth(getdate())
回答by Beth
SELECT DATEADD(day,1-DATEpart(day, GETDATE()),GETDATE())
SELECT DATEADD(day,1-DATEpart(day, GETDATE()),GETDATE())
回答by BlackICE
i think normally converts string to MM/DD/YY HH:mm:ss, you would need to use 08/01/2010 00:00:00
我认为通常将字符串转换为 MM/DD/YY HH:mm:ss，您需要使用 08/01/2010 00:00:00
Sorry, misunderstood the question, looking to see if you can change the order for strings.
抱歉，误解了这个问题，想看看您是否可以更改字符串的顺序。
This may be what you want:
这可能是你想要的：
declare @test as date
select @test = CONVERT(date, '01/08/2010 00:00:00', 103)
select convert(varchar(15), @test, 106)
回答by AllenG
回答by Quassnoi
SELECT CAST(FLOOR(CAST(DATEADD(d, 1 - DAY(GETDATE()), GETDATE()) AS FLOAT)) AS DATETIME)
回答by Todd181
SELECT DATEADD(m, DATEDIFF(m, 0, GETDATE()), 0)
This worked perfectly. I actually added a Case statement. Thanks for the post:
这工作得很好。我实际上添加了一个 Case 语句。感谢您的帖子：
SELECT Case(DATEADD(m, DATEDIFF(m, 0, GETDATE()), 0) as Date)
回答by Nicholas Thomson
Get First Day of Last Month
获取上个月的第一天
Select ADDDATE(LAST_DAY(ADDDATE(now(), INTERVAL -2 MONTH)), INTERVAL 1 DAY);
Get Last Day of Last Month
获取上个月的最后一天
Select LAST_DAY(ADDDATE(now(), INTERVAL -1 MONTH));
