SQL基础 学习小记四

1、带条件查询

      if()

          begin

          end

    else

          begin

          end

      while()

          begin

          end

案例1：计算1到100的累加和

declare @sum int

declare @n int

set @sum=0

set @n=1

while(@n<=100)

    begin

        set @sum=@sum+@n

        set @n=@n+1

    end

print @sum

按列2、计算1-100之间所有基数的和

declare @sum int
declare @n int
set @sum=0
set @n=1
while(@n<=100)
   begin
     if(@n%2<>0)
set @sum=@n+@sum
set @n=@n+1

   end
print @sum

2、事务transaction

begin  transaction

commit

rollback