FireDAC Components for Dataflex

Build 20.0.7587

Writing Data Access Code

This section provides a simple scenario that shows how to write the basic data access code needed to pipe Dataflex data into your application. The code example chains FireDAC components like TFDConnection and TFDQuery and executes a SELECT query with simple GUI components.

Setting Connection Properties

To begin accessing Dataflex through a TFDConnection component and then other FireDAC components, create a connection and link the FireDAC components:

  1. Initialize the Dataflex component: Add a TFDPhysCDSDriverLink object to your project.
  2. Link with a TFDConnection object: Set the DriverName property of the TFDConnection object to the Driver Id of the component, CData.CDS.
  3. Define connection properties through the TFDPhysCDSConnectionDefParams object. This object enables you to use Code Insight and compiler syntax checking.

FDConnection1.Name := 'SQLTest';
FDConnection1.DriverName := 'CData.CDS';
with FDConnection1.Params as TFDPhysCDataCDSConnectionDefParams do begin
    ...
end;

You can also set connection properties through the FDManager function. See Connection Definitions for other ways to define connections.

Execute SQL Queries to Dataflex

You can use the TFDQuery object to execute any SQL statement.

  1. Set the Connection property of a TFDQuery object to a TFDConnection instance.

  2. Set the Connected property of the TFDConnection object to True to open the connection.
  3. Call the Open method to execute SELECT queries with a TFDQuery object.

FDQuery1.Connection := FDConnection1;
FDConnection1.Connected := true;
FDQuery1.Active := true;
FDQuery1.Open('SELECT * FROM Accounts WHERE Name = ''MyAccount''');
To execute data manipulation statements, use the ExecSQL method -- both TFDConnection and TFDQuery have these methods, with slightly different functionality. See Manipulating Data for examples and more information.

See Querying Data for more information on selecting Dataflex data with the TFDQuery class.

Copyright (c) 2020 CData Software, Inc. - All rights reserved.
Build 20.0.7587