Delphi Learn How Easy It Is To Map Dataset Columns With A Table Adapter In FireDAC For Delphi

[FireWind]

Learn How Easy It Is To Map Dataset Columns With A Table Adapter In FireDAC For Delphi
March 6, 2021 By Konstantin Tomov

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 | Samplesand then navigate to:
  • Object PascalDatabaseFireDACSamplesDApt LayerMappingColumns
• Subversion Repository:
  • You can find Delphi code samples in Для просмотра ссылки Войди или Зарегистрируйся. 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;
    <em>// ...</em>
  begin
    <em>// create table adapter</em>
    FDCreateInterface(IFDDAptTableAdapter, oAdapt);

Assign command​

var
    oComm: IFDPhysCommand;
    <em>// ...</em>
  begin
    <em>// ...</em>
    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:

Для просмотра ссылки Войди или Зарегистрируйся
Для просмотра ссылки Войди или Зарегистрируйся