DateName () function and DatePart () function in SQL

Datepart () : Returns an integer representing the specified date part of the specified date

Syntax: Datepart (datepart, date) Return type: int

DateName (): returns a string representing the specified date part of the specified date

Syntax: DateName(datepart,date) 返回类型：nvarchar

Date part	abbreviation	Remarks
year	yy, yyyy	year
quarter	qq, q	Quarter
month	mm, m	month
dayofyear	dy, y	Day of the year
day	dd, d	day
week	wk, ww	Week of the year
weekday	The dw date part returns the number corresponding to a day of the week, for example: Sunday = 1	Day of the week
Hour	hh	hour
minute	my n	minute
second	ss, s	second
millisecond	ms	millisecond

select GETDATE () as 'Current date and time',
DateName(year,GetDate())+'-'+DateName(month,GetDate())+'-'+DateName(day,GetDate()) as '当前日期', 
DateName (quarter, GetDate ()) as 'first quarter',
DateName (week, GetDate ()) as 'Week of the year',
DateName (DAYOFYEAR, GetDate ()) as 'Day of the year',
DateName(year,GetDate()) as '年',
DateName(month,GetDate()) as '月',
DateName(day,GetDate()) as '日',
DateName(hour,GetDate()) as '时',
DateName(minute,GetDate()) as '分',
DateName(second,GetDate()) as '秒',
DateName(MILLISECOND,GetDate()) as '豪秒',
DateName (WEEKDAY, GetDate ()) as 'Day of the week'


select GETDATE () as 'Current date and time',
DatePart(year,GetDate())+'-'+DatePart(month,GetDate())+'-'+DatePart(day,GetDate()) as '当前日期', 
DatePart (quarter, GetDate ()) as 'first quarter',
DatePart (week, GetDate ()) as 'Week of the year',
DatePart (DAYOFYEAR, GetDate ()) as 'Day of the year',
DatePart(year,GetDate()) as '年',
DatePart(month,GetDate()) as '月',
DatePart(day,GetDate()) as '日',
DatePart(hour,GetDate()) as '时',
DatePart(minute,GetDate()) as '分',
DatePart(second,GetDate()) as '秒',
DatePart(MILLISECOND,GetDate()) as '豪秒',
DatePart (WEEKDAY, GetDate ()) as 'Day of the week'

search result:

Question: Why is the current date returned by DatePart 2023 instead of 2018-01-4?

note:

1）

Because the return type of DatePart is int, the result of the current date is the result of the operation

2）

In most English versions of SQL SERVER (and some traditional versions),

SELECT DATENAME (month, getdate ()) gets the string type January;

And in the simplified Chinese version: SELECT DATENAME (month, getdate ()) gets the string type 01

And SELECT DATEPART (month, getdate ()) in all versions get int type 1

3）

SELECT DATENAME (weekday, getdate ()) gets "week X"

SELECT DATEPART (weekday, getdate ()) gets the corresponding number of the week, one (1) / two (2) / three (3).

DateName () function and DatePart () function in SQL

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