adding columns to an existing table

I need to add around 600 columns to an existing table for testing purpose

declare @counter int
    set @counter = 1
    while @counter <开发者_如何学Python; 601
    begin

    ALTER TABLE Info ADD column+@counter varchar(max);
    set @counter = @counter + 1

    end

The column name should looks like column1,column2....column600

As this is purely for testing a quick and dirty way is to do this:

declare @counter int
set @counter = 1
declare @sql varchar(2000)

while @counter < 601
begin

Set @Sql = 'ALTER TABLE Info ADD column'+convert(varchar(10),@counter)+ ' varchar(max)'
Exec (@Sql)
set @counter = @counter + 1

end

Although I have to wonder why you would want 600 columns in a table

Use dynamic sql execution-

SET @str = 'ALTER TABLE Info ADD column' + CAST(@counter as varchar(5)) + ' varchar(max)';
EXEC ( @str );
GO

use Exec function:

Declare @SQL VarChar(1000)
Declare @vary varchar(100)
Declare @final varchar(1000)

SELECT @SQL = 'ALTER TABLE '
SELECT @SQL = @SQL + @TableName
select @vary = 'add column ' + id
select @final = @sql + @vary

Exec ( @final)
GO