create if not exists

create table stations (
    usaf INT default  0  not null,
    wban INT default  99999  not null,
    station_name CHAR( 40 ) not null,
    longtitude INT default  0  not null,
    latitude INT not null,
    elevation INT not null
); 

dbConnection.Connected := True;
  with dbCommand do
  begin
    CommandText := 'select * from systables where tabname = ''stations''';
    if Execute.RecordCount =  0  then
    begin
      with dbQuery do
      begin
        SQL.Clear;     
        SQL.Add('CREATE TABLE stations (');
        SQL.Add('usaf INT default 0 not null,');
        SQL.Add('wban INT default 99999 not null,');
        SQL.Add('station_name CHAR(40) not null,');
        SQL.Add('longtitude INT default 0 not null,');
        SQL.Add('latitude INT not null,');
        SQL.Add('elevation INT not null);');
        ExecSQL;
      end;
    end;
  end;