存储过程中如何按变量值建表(create table)

[lkfok]

存储过程中如何按变量值建表(create table)

[netease7688]

怎么发贴啊.在线等待中

[OracleRoob]

--用动态SQL。


declare @sql varchar(8000),@tbName varchar(100)

set @tbName = 'ttt'

set @sql = 'create table ' + @tbName + ' (id int)'

exec (@sql)

[OracleRoob]

动态sql语句基本语法
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, @sql nvarchar(4000)
set @sql='select count(*) from tableName'
exec(@sql)


--如何将exec执行结果放入变量中？

declare @num int, @sql nvarchar(4000)
set @sql='select @a=count(*) from tableName '
exec sp_executesql @sql,N'@a int output',@num output
select @num

[lkfok]

CREATE TABLE [dbo].[DF_SYSTEMDATA] (
[项目] [varchar] (20) COLLATE Chinese_PRC_CI_AS NULL ,
[值] [varchar] (20) COLLATE Chinese_PRC_CI_AS NULL ,
[值类型] [varchar] (1) COLLATE Chinese_PRC_CI_AS NULL
) ON [PRIMARY]
GO

INSERT INTO DF_SYSTEMDATA(项目,值) VALUES('最新年份','2008')
INSERT INTO DF_SYSTEMDATA(项目,值) VALUES('最新月份','1')
go

DECLARE @l_year char(15),@l_sql nvarchar(1000)
select @l_year='CW_YSDF'+值 from df_systemdata where 项目='最新年份'
set @l_sql='select * from dbo.sysobjects where name='+@l_year+' and type=''U''
CREATE TABLE '+@l_year+' ([dfid] [varchar] (10) COLLATE Chinese_PRC_CI_AS NOT NULL ,
[上月余额] [money] NULL ,
[本月电费] [money] NULL ,
[本月应收] [money] NULL ,
[本月未收] [money] NULL ,
[月份] [int] NOT NULL
) ON [PRIMARY]'

print @l_sql



where name='+@l_year+' 变量在这有问题

请老师告诉怎么用,谢谢！

[lkfok]

上面写错了

CREATE TABLE [dbo].[DF_SYSTEMDATA] (
[项目] [varchar] (20) COLLATE Chinese_PRC_CI_AS NULL ,
[值] [varchar] (20) COLLATE Chinese_PRC_CI_AS NULL ,
[值类型] [varchar] (1) COLLATE Chinese_PRC_CI_AS NULL
) ON [PRIMARY]
GO

INSERT INTO DF_SYSTEMDATA(项目,值) VALUES('最新年份','2008')
INSERT INTO DF_SYSTEMDATA(项目,值) VALUES('最新月份','1')
go


DECLARE @l_year char(15),@l_sql nvarchar(1000)
select @l_year='CW_YSDF'+值 from df_systemdata where 项目='最新年份'
set @l_sql='if exists(select * from dbo.sysobjects where name='+@l_year+' and type=''U'')
CREATE TABLE '+@l_year+' ([dfid] [varchar] (10) COLLATE Chinese_PRC_CI_AS NOT NULL ,
[上月余额] [money] NULL ,
[本月电费] [money] NULL ,
[本月应收] [money] NULL ,
[本月未收] [money] NULL ,
[月份] [int] NOT NULL
) ON [PRIMARY]'
--set @l_sql1='select * from dbo.sysobjects where name='+@l_year+' and type=''U'''
--if not exists
--exec @l_sql1
--print @l_year
print @l_sql



where name='+@l_year+' 变量在这有问题

请老师告诉怎么用,谢谢！

[lkfok]

应该是
if not exists()

[lwl0606]

set @l_sql='if not exists(select * from dbo.sysobjects where name='''+@l_year+''' and type=''U'')
CREATE TABLE '+@l_year+' ([dfid] [varchar] (10) COLLATE Chinese_PRC_CI_AS NOT NULL ,
[上月余额] [money] NULL ,
[本月电费] [money] NULL ,
[本月应收] [money] NULL ,
[本月未收] [money] NULL ,
[月份] [int] NOT NULL
) ON [PRIMARY]'
这样试试，你的没加引号在@l_year 两边

[lkfok]

lwl0606(寒泉)
谢谢！