Create proc Max_ID
@TableName varchar(50),
@Max_id int output as
declare @sql as nvarchar(2000) set @sql='select @Max_id =max(id) from '+ @TableNameexec sp_execute @sql,'@max_id int out',@max_id out
GO
@TableName varchar(50),
@Max_id int output as
declare @sql as nvarchar(2000) set @sql='select @Max_id =max(id) from '+ @TableNameexec sp_execute @sql,'@max_id int out',@max_id out
GO
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
Create proc Max_ID
@TableName varchar(50),
@Max_id int output as
declare @sql as nvarchar(2000) set @sql='select @Max_id =max(id) from '+ @TableName exec sp_executesql @sql,'@max_id int out',@max_id out
GO
[Microsoft][ODBC SQL Server Driver][SQL Server]过程需要参数 '@parameters' 为 'ntext/nchar/nvarchar' 类型。这个错误不知怎么回事
Create proc Max_ID
@TableName varchar(50),
@Max_id int output as
declare @sql nvarchar(2000) set @sql='select @Max_id =max(id) from '+ @TableName exec sp_executesql @sql,'@max_id int output',@max_id output
GO
@TableName varchar(50),
@Max_id int output as
declare @sql as nvarchar(2000) set @sql='select @Max_id =max(id) from '+ @TableName exec sp_executesql @sql,N'@max_id int out',@max_id out
GO
@TableName varchar(50),
@Max_id int output as
declare @sql as nvarchar(2000) set @sql='select @Max_id =max(id) from '+ @TableName exec sp_executesql @sql,N'@max_id int out',@max_id out
GO
exec sp_executesql @sql,N'@max_id int out',@max_id out 还要麻烦下可不可以解释下这句话的意思啊!小弟接触存储过程不多还忘指教!
执行可以多次重用或动态生成的 Transact-SQL 语句或批处理。Transact-SQL 语句或批处理可以包含嵌入参数。语法
sp_executesql [@stmt =] stmt
[
{, [@params =] N'@parameter_name data_type [,...n]' }
{, [@param1 =] 'value1' [,...n] }
]