sql multi-part identifier #TempTable.ColumnName could not be bound

Question

So I have a couple of temp tables I have created and am trying to move column contents from one table to another.

I populate #TempTable with values I'm gleaning from another table using a particular set of logic. Once I'm done with the current section I want to move the contents of #TempTable.ColumnName to another temp table (#Table1) that is housing the collected results of the logic sets.

This is how I've done it:

SET @ExecStatement = 'Alter table #Table1 Add  ' + @ColumnName +'  varchar(250)';
EXEC (@ExecStatement)
set @ExecStatement = 'Update #Table1 set #Table1.'+@ColumnName+' = #TempTable.ColumnName ';
exec (@execStatement)

The error message appears on the second SET statement.

Any help would be greatly appreciated.

Answer 1

Nothing more than an invalid update statement -- SQL can't tell where to pull the data from. Try this as the second set statement:

set @ExecStatement = 'Update #Table1 set ' + @ColumnName + ' = tt.TempConv from #Table1 ta inner join #TempTable tt on tt.Id = ta.Id

(replace "Id" with the proper column name)