Concatentating of variables issue - Getting Not a variable debugging.

Question

I'm building a insert statement based on a view I have by building
while stepping thru a bulk collect. I'm Concatentating my 4 varibles to
create a final sql statment that I want to use for Execute Immediate.
However when Concatentating the four variables the last variables for some
strang reason null out the variable.
While debugging I see all 4 variables populated ok, I played with changing the
variables lengths to see if that was the issue but I still have the issue.
Any idea why I would get "not a variable" when Concatentating the final variable?
Below is the Procedure with 2 lines showing the partial one that works and the
full line that fails.
CREATE OR REPLACE Procedure File_Load_Proc Is
Type Fl_Tab Is Table Of File_Load%Rowtype Index By Binary_Integer;
Recs Fl_Tab;
     ValCols Varchar2(1000);
     SelCols Varchar2(1000);
     SqlStatI Varchar2(200);
     SqlStatS Varchar2(200);
     FinalSql Varchar2(32767);
     v Integer;
VMp# Map.Mp#%Type := Null;
Procedure Get_Data
          Is
Begin
Select * Bulk Collect
Into Recs
From File_Load;
End Get_Data;
Procedure Perform_Insert
          Is
Begin
Null;
          --Execute Immediate FinalSql;
End Perform_Insert;
Procedure Process_FileLoad_Data
          Is
Begin
For Indx In 1 .. Recs.Count Loop
                    --First Record from Map
                         If Recs(Indx).RO# = 1 Then
                         If VMp# Is Null Then
                                   VMp# := Recs(Indx).MP#;
                              Elsif VMp# <> Recs(indx).MP# Then
     v := Length(SqlStatI || Rtrim(ValCols,',') || ') ' || RTrim(SelCols,',') || SqlStatS);
--This shows values the partial string values
     FinalSql := RTrim(SelCols,',') || SqlStatS;
                                        --When I add all the pieces to the sql statment the variable contains no data
FinalSql := SqlStatI || Rtrim(ValCols,',') || ')' || RTrim(SelCols,',') || SqlStatS;
                              Perform_Insert;
                              End If;
                              SqlStatI := 'Insert Into ' || Recs(Indx).SD_Into_Tb || ' (';
                              ValCols := Null;
                              SelCols := 'Select ';
                              SqlStatS := ' From ' || Recs(Indx).SD_Select_Tb || ';';
                         End If;
                         ValCols := ValCols || Recs(Indx).SD_Name_Out || ',';
                         SelCols := SelCols || Recs(Indx).SD_Name_In || ',';
End Loop;
               --Insert last Map Records;
FinalSql := SqlStatI || Rtrim(ValCols,',') || ')' || RTrim(SelCols,',') || SqlStatS;
     Perform_Insert;
End Process_FileLoad_Data;
Begin
Get_Data;
          -- Loop Thru Records and build Insert Statements
Process_FileLoad_Data;
Commit;
Exception
When Others Then
Rollback;
Raise;
End File_Load_Proc;

Answer 1

This could be an artifact of whatever front end program you're using to debug.
If I were you, I'd try adding debug statements (via your custom debug log package if you have one or via dbms_output.put_line if you haven't - not forgetting to set serveroutput on first *{;-) ) to record what each value was. That should help you to pinpoint what the issue might be.