The Commands sample shows you how to set up column mappings.

Location

You can find the MappingColumns sample project at:

• Start | Programs | Embarcadero RAD Studio Sydney | Samples and then navigate to:
  • Object PascalDatabaseFireDACSamplesDApt LayerMappingColumns
• Subversion Repository:
  • You can find Delphi code samples in GitHub Repositories. Search by name into the samples repositories according to your RAD Studio version.

How to Use the Sample

1. Navigate to the location given above and open MappingColumns.dproj.
2. Press F9 or choose Run > Run.
3. Click on the Use Connection Definition combo box and select an option.

Files

File in Delphi	Contains
MappingColumns.dproj MappingColumns.dpr	The project itself.
fMappingColumns.pas fMappingColumns.fmx	The main form.

Implementation

To set up the columns mapping, the sample implements the following steps.

Create table adapter

  var
    oAdapt: IFDDAptTableAdapter;
    // ...
  begin
    // create table adapter
    FDCreateInterface(IFDDAptTableAdapter, oAdapt);

Assign command

  var
    oComm: IFDPhysCommand;
    // ...
  begin
    // ...
    with oAdapt do begin
      FConnIntf.CreateCommand(oComm);
      SelectCommand := oComm;
      SelectCommand.Prepare('select * from {id FDQA_map1}');

Set source result set name

      SourceRecordSetName := EncodeName('FDQA_map1');

Set the DatSTable name

Set the DatSTable name where the rows are fetched.

      DatSTableName := 'mapper';

Set the UpdateTable name

      UpdateTableName := EncodeName('FDQA_map2');

Set the UpdateTable name

      UpdateTableName := EncodeName('FDQA_map2');

Setup column mappings

      ColumnMappings.Add('id1', 'num', 'id2');
      ColumnMappings.Add('name1', 'title', 'name2');

Fetch rows

      Define;
      Fetch;

Update changes to RDBMS

To append rows, implement the following code:

      for i := 0 to 9 do
        DatSTable.Rows.Add([i, 'first' + IntToStr(i)]); // Note that new rows will be added to the FDQA_map2(id2, name2) table.

Then, the sample updates the changes to the RDBMS.

      Update;

Please go to the link below if you want to check the original post of Embarcadero for this sample:

http://docwiki.embarcadero.com/CodeExamples/Sydney/en/FireDAC.MappingColumns_Sample

Head over and check out the full source code for the dataset mapping column example for FireDAC in Delphi Windows development.