Sqlº¯Êý´óÈ«

--¾ÛºÏº¯Êý
use pubs
go
select avg(distinct price)  --Ëãƽ¾ùÊý
from titles
where type='business'
go
use pubs
go
select max(ytd_sales)  --×î´óÊý
from titles
go
use pubs
go
select min(ytd_sales) --×îСÊý
from titles
go
use pubs
go
select type,sum(price),sum(advance)  --ÇóºÍ
from titles
group by type
order by type
go
use pubs
go
select count(distinct city)  --Çó¸öÊý
from authors
go
use pubs
go
select stdev(royalty) --·µ»Ø¸ø¶¨±í´ïʽÖÐËùÓÐÖµµÄͳ¼Æ±ê׼ƫ²î
from titles
go
use pubs
go
select stdevp(royalty) --·µ»Ø±í´ïʽÖÐËùÓÐÖƵÄÌî³äͳ¼Æ±ê׼ƫ²î
from titles
go
use pubs
go
select var(royalty) --·µ»ØËùÓÐÖµµÄͳ¼Æ·½²î
from titles
go
use pubs
go
select varp(royalty) --·µ»ØËùÓÐÖµµÄÌî³äµÄͳ¼Æ·½²î
from titles
go
--Êýѧº¯Êý
select sin(23.45),atan(1.234),rand(),PI(),sign(-2.34) --ÆäÖÐrandÊÇ»ñµÃÒ»¸öËæ»úÊý
--ÅäÖú¯Êý
SELECT @@VERSION --»ñÈ¡µ±Ç°Êý¾Ý¿â°æ±¾
SELECT @@LANGUAGE --µ±Ç°ÓïÑÔ
--ʱ¼äº¯Êý
select getdate() as 'wawa_getdate' --µ±Ç°Ê±¼ä
select getutcdate() as 'wawa_getutcdate' --»ñÈ¡utcʱ¼ä
select day(getdate()) as 'wawa_day' --È¡³öÌì
select month(getdate()) as 'wawa_month' --È¡³öÔÂ
select year(getdate()) as 'wawa_year' --È¡³öÄê
select dateadd(d,3,getdate()) as wawa_dateadd --¼ÓÈýÌì,×¢Òâ'd'±íʾÌì,'m'±íʾÔÂ,'yy'±íʾÄê,ÏÂÃæÒ»Ñù
select datediff(d,'2004-07-01','2004-07-15') as wawa_datediff --¼ÆËãÁ½¸öʱ¼äµÄ²î
select datename(d,'2004-07-15') as wawa_datename --È¡³öʱ¼äµÄijһ²¿·Ö
select datepart(d,getdate()) as wawa_datepart  --È¡³öʱ¼äµÄijһ²¿·Ö,ºÍÉÏÃæµÄÄǸö²î²»¶à
--×Ö·û´®º¯Êý
select ascii(123) as '123',ascii('123') as '"123"',ascii('abc') as '"abc"' --ת»»³ÉasciiÂë
select char(123),char(321),char(-123) --¸ù¾Ýasciiת»»³É×Ö·û
select lower('ABC'),lower('Abc'),upper('Abc'),upper('abc') --ת»»´óСд
select str(123.45,6,1), str(123.45,2,2) --°ÑÊýֵת»»³É×Ö·û´®
select ltrim('     "×ó±ßûÓпոñ"')  --È¥¿Õ¸ñ
select rtrim('"ÓÒ±ßûÓпոñ"     ') --È¥¿