b012_data, Object–Relational Mapping, the Spring Boot way for flutter.

Single row, then a whole list — inside one transaction.

insertObjet inserts a single entity. insertObjetList wraps a list of entities into a single atomic transaction. Both return a bool.

// CREATE — insert a single Person row.
final bool inserted = await DataAccess.instance.insertObjet(
  Person(newKey, 'KEBE', 'Birane', true, DateTime(2000, 8, 5)),
);

// CREATE (bulk) — insert several Persons inside a single transaction.
final bool personsListInserted =
    await DataAccess.instance.insertObjetList(<Person>[
  Person(newKey, 'Mbaye', 'Aliou', true, DateTime(1999, 5, 1)),
  Person(newKey, 'Cisse', 'Fatou', false, DateTime(2000, 7, 9)),
]);

One row, many rows, a single column, or several columns.

Predicates are plain SQL strings passed as afterWhere. Booleans are converted to 0/1 for SQLite automatically, so sex = true is equivalent to sex = 1.

// READ — fetch a single row matching an SQL predicate.
final Person? birane = await DataAccess.instance.get<Person>(
  Person(),
  "firstName = 'Birane' AND lastName = 'KEBE'",
);

// READ — fetch every row.
final List<Person>? everyone =
    await DataAccess.instance.getAll<Person>(Person());

// READ — fetch rows matching a predicate.
final List<Person>? men = await DataAccess.instance.getAllSorted<Person>(
  Person(),
  'sex = true',
);

Projection — single column or a set of columns:

// READ (projection) — pull a single column across the whole table.
final List<String> firstNames =
    await DataAccess.instance.getAColumnFrom<String, Person>('firstName');

final List<String> womenFirstNames = await DataAccess.instance
    .getAColumnFrom<String, Person>('firstName', afterWhere: 'sex = false');

// READ (projection) — pull several columns at once.
final List<Map<String, Object?>> nameRows = await DataAccess.instance
    .updateSomeColumnsOf<Person>('firstName, lastName');

final List<Map<String, Object?>> womenNameRows =
    await DataAccess.instance.updateSomeColumnsOf<Person>(
  'firstName, lastName',
  afterWhere: 'sex = 0',
);

Values follow the order columnsToUpdate + whereColumns.

Here: set firstName = 'developer' and lastName = '2022' where firstName = 'Birane' AND lastName = 'KEBE'.

final bool updated = await DataAccess.instance.updateSomeColumnsOf<Person>(
  <String>['firstName', 'lastName'],
  <String>['firstName', 'lastName'],
  <Object>['developer', '2022', 'Birane', 'KEBE'],
);

Remove rows matching a predicate, then count what’s left.

// DELETE — remove every row matching the predicate.
final bool deletedFatou = await DataAccess.instance.deleteObjet<Person>(
  "firstName = 'Fatou'",
);

// COUNT — total rows and filtered rows.
final int total = await DataAccess.instance.countElementsOf<Person>();
final int males = await DataAccess.instance.countElementsOf<Person>(
  afterWhere: 'sex = true',
);

Three directories exposed by the package.

final String databasesPath = await DiscData.instance.databasesPath; // SQLite files
final String filesPath     = await DiscData.instance.filesPath;     // user files
final String rootPath      = await DiscData.instance.rootPath;      // documents dir

One call writes text, Base64 or raw bytes.

// Save a text file into the default `files` directory.
final String? savedName = await DiscData.instance.saveDataToDisc(
  'contents of test.txt',
  DataType.text,
  takeThisName: 'test.txt',
);

// Save an Image (Base64) to the default `files` directory.
final String? testImage = await DiscData.instance.saveDataToDisc(
  testImageAsBase64,
  DataType.base64,
  takeThisName: 'testImage.png',
);

// Store a matching metadata row for that image.
final bool imageRecordCreated = await DataAccess.instance.insertObjet(
  Images('img0001', 'testImage.png', DateTime.now(), DateTime.now()),
);

As a string, Base64, bytes — or a Flutter widget.

// Exists?
final bool exists = await DiscData.instance.checkFileExists(fileName: 'test.txt');

// As a UTF-8 string.
final String? asString = await DiscData.instance.readFileAsString(fileName: 'test.txt');

// As Base64 — handy to ship blobs over JSON.
final String? asBase64 = await DiscData.instance.readFileAsBase64(fileName: 'testImage.png');

// As raw bytes — images, audio, video, PDFs, anything binary.
final Uint8List? asBytes = await DiscData.instance.readFileAsBytes(fileName: 'testImage.png');

// Straight into a Flutter `Image` widget.
final Image? asImage = await DiscData.instance.getImageFromDisc(imageName: 'testImage.png');

Metadata in SQLite, blobs on disk, one call to bind them.

Given a table Images with a column imageName that holds a file name on disk, fetch the raw bytes of the row where imageID = 'img0001':

final Uint8List? entityBytes = await DiscData.instance
    .getEntityFileOnDisc<Uint8List, Images>(
        'imageName', 'imageID', 'img0001');