我有个存储过程,在游标定义中想使用动态的表名应该怎么用呢。
CREATE PROCEDURE sp_cpx
@sjh varchar(30),@tmmc varchar(100),@tmlx varchar(100)
asdeclare @sql nvarchar(400)
declare @th varchar(30)
declare @nr int
declare @zd int
set @sql='select @nr=count(*) from '+@tmlx+' where sjh='''+@sjh+''' and tmmc='''+@tmmc+''''
exec sp_executesql @sql,N'@nr int output',@nr out
select @nr
set @sql='select @zd=max(th) from '+@tmlx+' where sjh='''+@sjh+''' and tmmc='''+@tmmc+''''
exec sp_executesql @sql,N'@zd int output',@zd outif @zd>@nr
begin
--declare youbiao cursor local scroll_locks for select * from dxxzt where sjh=@sjh and tmmc=@tmmc
exec('declare youbiao cursor local scroll_locks for select * from '+@tmlx+' where sjh='''+@sjh+''' and tmmc='''+@tmmc+'''')
open youbiao
fetch next from youbiao
while @@fetch_status=0
begin
set @th=1
set @sql='update '+@tmlx+' set th='''+@th+''' where sjh='''+@sjh+''' and tmmc='''+@tmmc+''''
exec(@sql)
set @th=@th+1
fetch next from youbiao
end
close youbiao
deallocate youbiao
end
GO在网上看到很多说用exec('declare youbiao cursor local scroll_locks for select * from '+@tmlx+' where sjh='''+@sjh+''' and tmmc='''+@tmmc+'''')这样执行但是这样不行呢。在查询分析器中显示服务器: 消息 16916,级别 16,状态 1,过程 sp_cpx,行 19
名为 'youbiao' 的游标不存在。是我这个类型的游标不能这样用还是这样用只是在EXEC中运行局部游标。是不是要定义全局游标,如果要应该怎么定义呢??
如果不是这样拿应该怎么做呢?
CREATE PROCEDURE sp_cpx
@sjh varchar(30),@tmmc varchar(100),@tmlx varchar(100)
asdeclare @sql nvarchar(400)
declare @th varchar(30)
declare @nr int
declare @zd int
set @sql='select @nr=count(*) from '+@tmlx+' where sjh='''+@sjh+''' and tmmc='''+@tmmc+''''
exec sp_executesql @sql,N'@nr int output',@nr out
select @nr
set @sql='select @zd=max(th) from '+@tmlx+' where sjh='''+@sjh+''' and tmmc='''+@tmmc+''''
exec sp_executesql @sql,N'@zd int output',@zd outif @zd>@nr
begin
--declare youbiao cursor local scroll_locks for select * from dxxzt where sjh=@sjh and tmmc=@tmmc
exec('declare youbiao cursor local scroll_locks for select * from '+@tmlx+' where sjh='''+@sjh+''' and tmmc='''+@tmmc+'''')
open youbiao
fetch next from youbiao
while @@fetch_status=0
begin
set @th=1
set @sql='update '+@tmlx+' set th='''+@th+''' where sjh='''+@sjh+''' and tmmc='''+@tmmc+''''
exec(@sql)
set @th=@th+1
fetch next from youbiao
end
close youbiao
deallocate youbiao
end
GO在网上看到很多说用exec('declare youbiao cursor local scroll_locks for select * from '+@tmlx+' where sjh='''+@sjh+''' and tmmc='''+@tmmc+'''')这样执行但是这样不行呢。在查询分析器中显示服务器: 消息 16916,级别 16,状态 1,过程 sp_cpx,行 19
名为 'youbiao' 的游标不存在。是我这个类型的游标不能这样用还是这样用只是在EXEC中运行局部游标。是不是要定义全局游标,如果要应该怎么定义呢??
如果不是这样拿应该怎么做呢?
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 几个是几个相关实例:--1. 使用 EXEC 实现的动态参数存储过程
CREATE PROC p_test
@para1 varchar(10)=null,
@para2 varchar(10)=null,
@para3 varchar(10)=null,
@para4 varchar(10)=null
AS
SET NOCOUNT ON
DECLARE @sql varchar(8000)
SET @sql='SELECT * FROM tbname WHERE 1=1'
IF @para1 IS NOT NULL
SET @sql=@sql+' AND col1='''+@para1+''''
IF @para2 IS NOT NULL
SET @sql=@sql+' AND col2='''+@para2+''''
IF @para3 IS NOT NULL
SET @sql=@sql+' AND col3='''+@para3+''''
IF @para4 IS NOT NULL
SET @sql=@sql+' AND col4='''+@para4+''''
EXEC(@sql)
GO
/*======================================================*/--2. 使用 sp_executesql 实现的动态参数存储过程
CREATE PROC p_test
@para1 varchar(10)=null,
@para2 datetime=null,
@para3 varchar(10)=null,
@para4 int=null
AS
SET NOCOUNT ON
DECLARE @sql nvarchar(4000)
SET @sql='SELECT * FROM tbname WHERE 1=1'
+CASE WHEN @para1 IS NULL THEN '' ELSE ' AND col1=@para1' END
+CASE WHEN @para2 IS NULL THEN '' ELSE ' AND col2=@para2' END
+CASE WHEN @para3 IS NULL THEN '' ELSE ' AND col3=@para3' END
+CASE WHEN @para4 IS NULL THEN '' ELSE ' AND col4=@para4' END
EXEC sp_executesql @sql,N'
@para1 varchar(10)=null,
@para2 datetime=null,
@para3 varchar(10)=null,
@para4 int=null
',@para1,@para2,@para3,@para4
GO
/*======================================================*/--3. 不使用动态 Transact-SQL 语句实现的动态参数存储过程
CREATE PROC p_test
@para1 varchar(10)=null,
@para2 datetime=null,
@para3 varchar(10)=null,
@para4 int=null
AS
SET NOCOUNT ON
SELECT * FROM tbname
WHERE (@para1 IS NULL OR col1=@para1)
AND (@para2 IS NULL OR col2=@para2)
AND (@para3 IS NULL OR col3=@para3)
AND (@para4 IS NULL OR col4=@para4)
exec('declare youbiao cursor scroll_locks for select * from '+@tmlx+' where sjh='''+@sjh+''' and tmmc='''+@tmmc+'''')
这样就行了。