SQL 数据库中怎么找到一行数据并修改啊？

一是多写几个更新语句,一次更新一个字段

二是把更新语句,拼接成string形式,最后一次执行.

或用 @@rowcount判断是否存在：

create procedure alStuentsInfor

@StuId char(10),

@StuImage IMAGE=null,

@StuName varchar(20)=null,

@StuSex char(5)=null, @StuAge smallint=null

AS

BEGIN

UPDATE dbo.Students

SET iStuImage = ISNULL(@StuImage,iStuImage),

vStuName = ISNULL(@StuName,vStuName),

cStuSex = ISNULL(@StuSex,cStuSex),

sStuAge = ISNULL(@StuAge,sStuAge)

WHERE cStudentsId = @StuId

IF @@ROWCOUNT>0

RETURN 0

ELSE

begin

PRINT'NO RECORDS FOUND!'

RETURN 1

END

END

GO

IF--THEN语句结合 

复制代码 代码如下:

UPDATE mytable 

SET myfield = CASE other_field 

WHEN 1 THEN 'value' 

WHEN 2 THEN 'value' 

WHEN 3 THEN 'value' 

END 

WHERE id IN (1,2,3)

我们可以使用以下SQL语句： 

复制代码 代码如下:

UPDATE categories 

SET display_order = CASE id 

WHEN 1 THEN 3 

WHEN 2 THEN 4 

WHEN 3 THEN 5 

END, 

title = CASE id 

WHEN 1 THEN 'New Title 1' 

WHEN 2 THEN 'New Title 2' 

WHEN 3 THEN 'New Title 3' 

END 

WHERE id IN (1,2,3)