Check if field exists

[oz8hp]

I have got the problem that I need to check if a field exists in a table but since the app runs on both MS Access and MySQL I need a way to do it in general.

(I use an old version 3 of UniDAC but company won't upgrade since this version works OK for our needs)

[AndreyZ]

You can use the TUniMetaData component for this. Here is code example:

Code: Select all

procedure TForm1.Button1Click(Sender: TObject);
begin
  UniMetaData1.MetaDataKind := 'Columns';
  if AnsiSameText(UniMetaData1.Connection.ProviderName, 'MySQL') then // MS Access does not support schemas
    UniMetaData1.Restrictions.Values['TABLE_SCHEMA'] := 'databasename';
  UniMetaData1.Restrictions.Values['TABLE_NAME'] := 'tablename';
  UniMetaData1.Restrictions.Values['COLUMN_NAME'] := 'columnname';
  UniMetaData1.Open;
  if not UniMetaData1.Eof then
    ShowMessage('Field exists')
  else
    ShowMessage('Field does not exist');
end;