把条件做为变量传到存储过程中,然后用动态SQL完成.
例如:CREATE PROCEDURE my_proc
@con1 varchar(50),
@con2 varchar(50),
@con3 varchar(50),
@con4 varchar(50)
AS
begin
declare @sql as varchar(1000)
set @sql = 'select * from tb '
if @con1 <> '' or @con1 is not null
set @sql = @sql + ' where ' + @con1 + ' '
if @con2 <> '' or @con2 is not null
set @sql = @sql + @con2
if @con3 <> '' or @con3 is not null
set @sql = @sql + @con3
if @con4 <> '' or @con4 is not null
set @sql = @sql + @con4
exec(@sql)
end
goexec my_proc ' id = 1 ' , ' or id = 2 ' , ' or id = 3' , ' or id = 4'
例如:CREATE PROCEDURE my_proc
@con1 varchar(50),
@con2 varchar(50),
@con3 varchar(50),
@con4 varchar(50)
AS
begin
declare @sql as varchar(1000)
set @sql = 'select * from tb '
if @con1 <> '' or @con1 is not null
set @sql = @sql + ' where ' + @con1 + ' '
if @con2 <> '' or @con2 is not null
set @sql = @sql + @con2
if @con3 <> '' or @con3 is not null
set @sql = @sql + @con3
if @con4 <> '' or @con4 is not null
set @sql = @sql + @con4
exec(@sql)
end
goexec my_proc ' id = 1 ' , ' or id = 2 ' , ' or id = 3' , ' or id = 4'
1 :普通SQL语句可以用Exec执行 eg: Select * from tableName
Exec('select * from tableName')
Exec sp_executesql N'select * from tableName' -- 请注意字符串前一定要加N 2:字段名,表名,数据库名之类作为变量时,必须用动态SQL eg:
declare @fname varchar(20)
set @fname = 'FiledName'
Select @fname from tableName -- 错误,不会提示错误,但结果为固定值FiledName,并非所要。
Exec('select ' + @fname + ' from tableName') -- 请注意 加号前后的 单引号的边上加空格 当然将字符串改成变量的形式也可
declare @fname varchar(20)
set @fname = 'FiledName' --设置字段名 declare @s varchar(1000)
set @s = 'select ' + @fname + ' from tableName'
Exec(@s) -- 成功
exec sp_executesql @s -- 此句会报错 declare @s Nvarchar(1000) -- 注意此处改为nvarchar(1000)
set @s = 'select ' + @fname + ' from tableName'
Exec(@s) -- 成功
exec sp_executesql @s -- 此句正确 3. 输出参数
declare @num int,
@sqls nvarchar(4000)
set @sqls='select count(*) from tableName'
exec(@sqls)
--如何将exec执行结果放入变量中? declare @num int,
@sqls nvarchar(4000)
set @sqls='select @a=count(*) from tableName '
exec sp_executesql @sqls,N'@a int output',@num output
select @num
静态的就用IF ELSE,不过分支比较多,,,
@A int=null
,@B int=null
,@C int=null
,@D int=null
,@E int=null
,@F int=null
,@G int=null
,@H int=null
,@I int=null
as
begin
select * from 表一
where A=isnull(@A, A) and B=isnull(@B, B) and C=isnull(@C, C) select * from 表二
where D=isnull(@D, D) and E=isnull(@E, E) and F=isnull(@F, F) select * from 表三
where G=isnull(@G, G) and H=isnull(@H, H) and I=isnull(@I, I)
end
go