declare @Name varchar(50)
declare @upoint int,@birthday datetime

--声明一个变量
declare @Name varchar(50)
--同时声明两个变量
declare @upoint int, @birthday datetime
/*可以这样赋值*/
set @Name = ‘小新‘
set @upoint = 200
select @birthday = ‘1990-5-8‘
/*也可以这样赋值*/
set @Name = ‘小新‘
select @upoint = 200,@birthday = ‘1990-5-8‘ from customers

/*第一步：得到喜来乐的积分*/
declare @upoint int
select @upoint = upoint from customers 
where customername=‘喜来乐‘
/*第二步:执行带有条件的查询语句*/
select * from customers where upoint > @ upoint

declare @name varchar(50)
declare @upoint int
use booksmanager
select @name=customername,@upoint =upoint 
from customers 
where customerid=‘10008‘
print  ‘姓名:‘+@name
print  ‘积分:‘+str(@upoint,5)

--示例
if @myavg >70
   begin
     print ‘c#编程成绩优秀，前三名考试信息是:‘
     select top 3 * from score 
     where courseno=@courseid 
     order by score desc
   end
else
  begin
     print ‘c#编程成绩较差，后三名考试信息是：‘
     select top 3 * from score 
     where courseno=@courseid 
     order by score 
 end

use master
if exists (select * from sysdatabases where name=‘booksmanager‘)
   drop database booksmanager

select stuno,成绩=
case
    when score<60 then ‘E‘
    when score between 60 and 69 then ‘D‘
    when score between 70 and 79 then ‘C‘
    when score between 80 and 89 then ‘B‘
    else ‘A‘
end
from Score
where courseno=@courseid

while @pass/@total <0.8
begin
     update Score set score = score+2 where courseno=@courseid
     select @pass = count(*) from Score where courseno=@courseid and score>=60
end

use myschool
go --批处理标志
select * from course1  --并不存在course1
select * from student
go --批处理标志

/**
  块注释用于描述性文字较多的场合
  ........
  ........
**/