请教set和select 的区别 - 未名空间MITBBS历史存档

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请教set和select 的区别

请教set和select 的区别# Database - 数据库

c*t2003-12-01 08:12

1 楼

In a SP
declare @x int
declare @y int
...
what's the difference between "set @[email protected] " and "select @[email protected]"
Thx.

c*t2003-12-01 08:12

2 楼

Who can tell the difference?
555~~~~~~~~~~~~

【在 c**t 的大作中提到】

: In a SP
: declare @x int
: declare @y int
: ...
: what's the difference between "set @[email protected] " and "select @[email protected]"
: Thx.

n*m2003-12-01 08:12

3 楼

where you can use:
select @y = @x?
it is not sql!!!!!!!!

【在 c**t 的大作中提到】

: Who can tell the difference?
: 555~~~~~~~~~~~~

c*t2003-12-01 08:12

4 楼

No problem.
I tried this in query analyzer.

【在 n**m 的大作中提到】

: where you can use:
: select @y = @x?
: it is not sql!!!!!!!!

t*k2003-12-01 08:12

5 楼

在Sybase中
好象要用
select @[email protected] 来赋值吧
有点儿忘了

【在 c**t 的大作中提到】

: In a SP
: declare @x int
: declare @y int
: ...
: what's the difference between "set @[email protected] " and "select @[email protected]"
: Thx.

aw2003-12-01 08:12

6 楼

copied from online

c*t2003-12-01 08:12

7 楼

Interesting. I thought it's rather than that.
I have a SP to do some calculation (as follows). If I use set (--###),
some of '--*' will print " 390 0 ", after that all *B will be 0.
If I use select the two numbers are always the same. That's why I brought
this question.
while (@@fetch_status <> -1)
select @v1=isnull(field, 0) from table1 where @cur_x ..
select @v2=isnull(field, 0) from table2 where @cur_x ...
set @[email protected] --###
set @[email protected] --###
print cast(@v1 as varchar)

【在 aw 的大作中提到】

: copied from online