SQLite: Tutorial Project

Preparations

1. If you haven't done so already, create a new folder \DelphiLand.
2. If you haven't done so already, create directory SQLiteGeo "under" \DelphiLand.
3. Next, download sqlitegeo.zip and unzip it to this directory.

A closer look

1. Start Delphi and open sqlitegeo.dpr.
2. In the the menu, select Project / Options...
3. In the dialog that appears, select Delphi Compiler / Output directory
   Clear this option and click OK. 
   That way, you avoid the need to enter a hardwired full path when setting FDConnection.Params.Database (see later).
4. Open Delphi's File menu and click Save All.

5. The structure of the table Countries of database Geo.sqlite is as follows:

   Field name	Type
   name	varchar(50)
   code	varchar(10)
   population	numeric
   currency	varchar(25)
   curcode	varchar(10)

6. In Design Mode, let's have a look at the components:
   
   
   • FDConnection1 is a FireDac connection: it defines the connection parameters, establishes a connection to a DBMS (DataBase Management System) and manages the associated datasets.
   • qCountries is a TDFQuery (FireDAC Query). Its property Connection is set to FDConnection1 and its property SQL is set to
                     select * from countries
     ...meaning: select all fields from table countries
   • dsCountries is a TDataSource, the interface between a dataset component and data-aware controls. Its property DataSet is set to qCountries.
   • gridCountries is a TDBGrid (DataBase Grid) that is used to visualize the contents of the table Countries. Its property DataSource is set to dsCountries.
   • DBNavigator1 is used to move through the data in the dataset and perform operations on the data, such as inserting a record or posting a record. Its property DataSource is set to dsCountries.
   • FDGUIxWaitCursor1 is a component that is needed for every FireDac application.
7. Since most work has been done in Design Mode, the source code for this project is really minimal:
   

   procedure TForm1.FormShow(Sender: TObject);
   begin
     FDConnection1.Close;
     FDConnection1.Params.Clear;
     FDConnection1.Params.Add('DriverID=SQLite');
     FDConnection1.Params.Add('Database=geo.sqlite');
     FDConnection1.Open;
     qCountries.Open;
   end;
   
   procedure TForm1.FormDestroy(Sender: TObject);
   begin
     qCountries.Close;
     FDConnection1.Close;
   end;