Hi, The code below works fine in dbisam but when I run it using an elevatedb table it compiles happily but crashes somewhere on the line containing the DataTypeToDisplayString().  Should I have changed it to something else?
Any help appreciated.
Col

     with FieldDefs do
     begin
       for I:=0 to Count-1 do
       begin
         with TargetTable do
         begin
           Append;
           FieldByName('Position').AsInteger     := I+1;
           FieldByName('FieldName').AsString   := Items[I].Name;
           FieldByName('DataType').AsString     := DataTypeToDisplayString(Items[I].DataType);
           FieldByName('Size').AsInteger           := Items[I].Size;
           FieldByName('Required').AsBoolean   := Items[I].Required;
           //FieldByName('Description').AsString := Items[I].Description;
           FieldByName('TableName').AsString   := TargetName;
           Post;
         end;
       end;
     end;

Forgot to mention, the error displayed is just a "Access violation at address..." error.

this is the code that's in the DataTypeToDisplayString function...

function DataTypeToDisplayString(DataType: TFieldType): string;
var
  DataTypePos: Integer;
begin
  Result:='Unknown';
  with DataTypesList do
     begin
     DataTypePos:=IndexOfObject(TObject(DataType));
     if (DataTypePos <> -1) then
        Result:=DataTypesList[DataTypePos];
     end;
end;

Colin


Have you tried tracing into the function. An AV usually means that an object hasn't been instantiated. In this case probably DataTypesList

Roy Lambert [Team Elevate]

Colin,

<< Hi, The code below works fine in dbisam but when I run it using an
elevatedb table it compiles happily but crashes somewhere on the line
containing the DataTypeToDisplayString().  Should I have changed it to
something else? >>

That function is specific to DBISAM and is only intended for use with the
DBISAM utilities.

--
Tim Young
Elevate Software
www.elevatesoft.com

<<That function is specific to DBISAM and is only intended for use with the
DBISAM utilities.>>

I'm wanting to create a dictionary of fields contained within my database. Is there another way I can determine what the field type is in an elevatedb table?

Colin


><<That function is specific to DBISAM and is only intended for use with the
>DBISAM utilities.>>
>
>I'm wanting to create a dictionary of fields contained within my database. Is there another way I can determine what the field type is in an elevatedb table?

I'm not sure why you want to do this. With ElevateDB there is already a dictionary of fields - its the catalog.

To see what I mean go into EDBManager, select your database and then run the following sql

select * from information.tablecolumns

Roy Lambert [Team Elevate]

Hi Roy,
In my app I want to include a feature where my clients can customise the text captions for the various edit fields, as well as customising Hint descriptions and the like.  As part of that feature I want to tell them what type of data can be entered into each field and what the maximum field length is.  I also want to be able to add a utility function for myself that looks at all the fields of various tables and ensures that I haven’t created fields that are a certain size in a table and a completely different size(or data type) in another.
In the past I’ve done this by importing the table columns info into a table rather than using an external app such as the EDBManager.  My problem is I can retrieve the table name, field name and size and put them into the appropriate field in a table, but I can’t seem to get the field type description, which is a necessary element of the process.
Col

Colin


OK you haven't made the mental leap between DBISAM and ElevateDB yet<vbg>

With DBISAM the field definitions were stored in the table files (the .dat as I remember) with ElevateDB ALL (and I do mean ALL) of the database definitions are stored in the catalog. This is a separate file from the tables. Any and all of the information relating to the table definitions can now be found by querying the catalog. If you look up Information schema and Configuration database in the OLH you'll start to get an idea of what's there.

Its one hell of a shift of mind set and it took me a long time to get part of the way there as it will anyone not used to operating with SQL.

I used EDBManager as a method of quickly letting you see what was there. What you need to do for your app is create a query the SQL would be:


select Name,Type, Length, (NOT Nullable), Description, ??? from information.tablecolumns


I have no idea where TargetName will come from

and then use the resultset as you do the current table.

Be warned though, if you want to edit this result set you can't. You'll have to create either a temporary table or an in-memory table to do this.


Roy Lambert [Team Elevate]

<<OK you haven't made the mental leap between DBISAM and ElevateDB yet<vbg> >>

Hi Roy, I thought I had, but <sigh> it seems not.  Thanks for pointing me in the right direction.  I appreciate the help.
Col