Rename the columns of a SQL table with field values of a table

Question

Im trying to execute a SQL query that will rename the columns of a table with the text from the first recordset in a table.

My table looks like this:

 COL1  |  COL2  |  COL3  |  COL4  |  COL5  | COL6

 REASON |ITEMDATE|ITEMTIME|SITENAME|  EVENT | RPM  
 tstamp |12-11-07|  24:12 | Spain1 |Shutdwn | 1000  
 tstamp |13-11-07|  02:22 | Spain1 |Startup | 1050

And I would like to rename the columns like this:

 REASON |ITEMDATE|ITEMTIME|SITENAME|  EVENT | RPM

 tstamp |12-11-07|  24:12 | Spain1 |Shutdwn | 1000  
 tstamp |13-11-07|  02:22 | Spain1 |Startup | 1050 

Answer 1

This procedure will do what you need. You can run it as follows:

    exec p_rename_columns N'<mytable>'

Note that the procedure assumes that the "first" row is the physical first row on disk. Since this can change depending on which field the clustered index on the table uses it is not 100% guaranteed.

The code for the procedure:

create proc p_rename_columns (@table sysname)
AS

declare @name sysname, 
        @col sysname,
        @sql nvarchar(max)

declare cur cursor 
local read_only 
for select name 
      from sys.columns 
     where object_id = object_id(@table)

open cur
fetch next from cur into @name

while @@fetch_status = 0 
  begin

    select @sql = N'select top (1) @col = ' + quotename(@name) + N' from ' + quotename(@table)
    exec sp_executesql @sql, N'@col sysname output', @col output

    select @sql = N'exec sp_rename ''' + quotename(@table) + N'.' + quotename(@name) + N''', ''' + @col + N''''
    exec (@sql)

    fetch next from cur into @name
  end 
close cur
deallocate cur

select @sql = N'DELETE TOP (1) from ' + quotename(@table)
exec (@sql)
GO