Very Computer

Hi,

I got delphi several days ago and am trying to save the live data into a
.dbf file. Sorry if this question has been asked.

In SQL, you can do:
        INSERT INTO newtable
                SELECT * FROM oldtable
Here newtable and oldtable have the same structure.

Delphi BDE does not support this. What I want to know is how I can save a
TQuery result into a .dbf file instead of live data in TDBGrid?

Albert Pu

Quote:>I got delphi several days ago and am trying to save the live data into a
>.dbf file. Sorry if this question has been asked.

>In SQL, you can do:
>        INSERT INTO newtable
>                SELECT * FROM oldtable
>Here newtable and oldtable have the same structure.

>Delphi BDE does not support this. What I want to know is how I can save a
>TQuery result into a .dbf file instead of live data in TDBGrid?

I am trying to do this as well.  I am writing a Delphi CGI program
that will transfer dbase files across the network that match criteria
entered on a webpage.

The TQuery is nice, because I can dynamically specify the database at
runtime, and so the same program can access any of a number of databases.

What I started working on last night was to use a ttable object to
create a new database (using TTable.CreateTable) with the same structure
as the database I am querying.  I would then use batch move to copy
the records.

The code goes something like this: (Source is a TQuery, NewTable a TTable)

Source.Open;
With NewTable do
  begin
  Active := False;
  DataBaseName := 'c:\tempfile';
  TableName := 'temp.dbf';
  TableType := ttDefault;
  FieldDefs := Source.FieldDefs;
  IndexDefs.Clear;
  CreateTable;
  BatchMove(Source, batCopy)
  Close;
  end;
end;

The problem seems to be in the FieldDefs line.  When I run this program
I (not surprisingly) get an exception saying "bad field def" at the
CreateTable line.

I am pretty sure that I need to copy the FieldDefs one by one to the
NewTable object.  Unfortunately, it looks to me like I will have to
decompose the fielddefs from the TQuery since there is no Add(TFieldDef)
method for FieldDefs. That's my project for this afternoon.

I'll let you know if I have any luck.

Of course, any advice from someone who has done this before would be
appreciated!

Thanks,
Brian

Quote:>What I want to know is how I can save a
>TQuery result into a .dbf file instead of live data in TDBGrid?

Here is the code that I came up with (Thanks to Steve Koterski for
his pointer to the TBatchMove Component).

aSource is a TQuery component which was dropped on the main form at
design time.  I entered the information for it in the Object Inspector,
but no reason why you couldn't instantiate it at run time.

This will create (or overwrite) the dbase file:
'd:\database\programs\copy\temp.dbf' using the results of the TQuery.

{-- QueryRunClick ----------------------------------------------------}
procedure TForm1.QueryRunClick(Sender: TObject);
Var
  NewTable: TTable;
  CreateNew: TBatchMove;
begin
aSource.Open;
NewTable := TTable.Create(Self);
With NewTable do
  begin
  DatabaseName := 'd:\database\programs\copy';
  TableName := 'temp.dbf';
  TableType := ttDBase;
  end;
CreateNew := TBatchMove.Create(Self);
With CreateNew do
  begin
  Source := aSource;
  Destination := NewTable;
  Mode := batCopy;
  Execute;
  end;
CreateNew.Free;
NewTable.Free;
aSource.Close;
end;