FireDAC.SQLiteIniFile Demo Sample

This sample uses FireDAC to connect to an SQLite database that emulates the structure and the operations of an INI File.

Location

You can find the SQLiteIniDemo project at:

• Start | Programs | Embarcadero RAD Studio Rio | Samples and then navigate to:
  • Object Pascal\Database\FireDAC\Samples\AddOn\SQLiteIniFile\Demo
• Subversion Repository:
  • You can find Delphi code samples in GitHub Repositories. Search by name into the samples repositories according to your RAD Studio version.

Description

• This application reads and writes data to an INI file using a FireDAC database connection as its storage medium, instead of a plain text file.

Note: The connection to the database does not require authentication.

How to Use the Sample

1. Navigate to the location given above and open SQLiteIniDemo.dproj.
2. Press F9 or choose Run > Run.
3. Click the Write to IniFile button and the program will create a database (IniFile.db) and fill it with data.
4. The data from the database that was just created is displayed in a TDBGrid.
5. You can manipulate the data with a TDBNavigator.
6. Click the Read from IniFile button to display the data from the database in a TMemo and the image from the database in a TImage.

Files

File	Contains
Demo\data\ winmacmachine.bmp	Contains the image that is diplayed in the TImage.
Demo\SQLiteIniDemo.dproj	Contains the project itself.
Demo\Unit1.dfm	Contains the code of the main form.
Demo\Unit1.pas	Contains the main form and the main code.
FireDAC.Phys.SQLiteIniFile.pas	Contains the code for the SQLiteIniFile class used for writting/reading to/from the IniFile.db.
ReadMe.txt	Contains information about FireDAC.Phys.SQLiteIniFile.pas.

Implementation

• The project uses a TFDConnection to establish a connection with a database (IniFile.db), which will be used to write or read data.

• In order to display the data from the database, the project uses a TFDQuery, a TDataSource, and a TFDPhysSQLiteDriverLink.
• The data will be displayed in a TDBGrid.
• You can navigate through the data with a TDBNavigator.

• The TFDQuery uses the following query:

 SELECT
   B.SECTION_NAME AS "Section::varchar(32)",
   A.KEY_NAME AS "Name::varchar(32)",
   CASE WHEN LENGTH(A.KEY_VALUE) <= 32 THEN A.KEY_VALUE
   ELSE '(blob)' END AS "Value::varchar(32)"
 FROM KEYS A
 LEFT JOIN SECTIONS B ON B.SECTION_ID = A.SECTION_ID

• In the FireDAC.Phys.SQLiteIniFile.pas unit, several classes (TFDSQLiteIniFileDB and TFDSQLiteIniFile) are defined for interacting with the database.
  • Click the Write to IniFile button on the main form to create and initialize a TFDSQLiteIniFile instance (the oIniFile code variable) and to create the "IniFile.db" database. After this, a string (abcd...), an integer (123), a float (567.89), a date time (Now), and an image (the image from the data folder) are added to the database. The data that was just inserted in the database is displayed in a TDBGrid.

    Note: As shown by the TFDQuery SQL command, when "LENGTH(A.KEY_VALUE) > 32", TDBGrid will display "(blob)" instead of the actual value.

  • Click the Read from Inifile button on the main form to read from the database and display the string, the integer, the float, and the date time in a TMemo and the image will be displayed in a TImage.

Uses

• FireDAC.Comp.Client.TFDConnection
• FireDAC.Comp.Client.TFDQuery
• FireDAC.Phys.SQLite.TFDPhysSQLiteDriverLink
• Data.DB.TDataSource
• Vcl.DBGrids.TDBGrid
• Vcl.DBCtrls.TDBNavigator
• Vcl.ExtCtrls.TImage
• Vcl.StdCtrls.TMemo

See Also

• Using TIniFile and TMemIniFile

Tutorials

• Tutorial: Using FireDAC from a Multi-Device Application on Desktop Platforms