flora_orm 2.0.5

Flutter plugin for ORM in front of storage like sqflite and shared_preferences

flora_orm

Database ORM (Object-Relational Mapping) for Flutter.

The ORM supports:

• shared_preferences - All platforms support
• sqflite - iOS/Android/MacOS support
• sqflite_common_ffi - on disk - iOS/Android/MacOS/Linux/Windows support
• sqflite_common_ffi - in memory - iOS/Android/MacOS/Linux/Windows support

Getting Started

To get started, you need to add flora_orm to your project. Follow the steps below:

1. Open the terminal in your project root. You can do this by pressing Alt+F12 in Android Studio or Ctrl+` in VS Code.

2. Run the following command:

flutter pub add flora_orm

This command will add a line to your package's pubspec.yaml file and run an implicit flutter pub get.
The added line will look like this:

dependencies:
  flora_orm: 

Usage example

Import flora_orm.dart

import 'package:flora_orm/flora_orm.dart';

Initializing

To use flora_orm, you need to create entity classes that satisfy the following:

• Naming conversion is {entity_name}.entity.dart. For example user.entity.dart (recommended).
• You must add 2 parts to the top of the entity file: {entity_name}.entity.g.dart and {entity_name}.entity.migrations.dart.
• You must annotate the class with @entity (or @OrmEntity() for granular control).
• Your entity class must extend Entity<{YourEntityName}, {YourEntityName}Meta> with _{YourEntityName}Mixin, {YourEntityName}Migrations.

Example Entity

import 'package:flora_orm/flora_orm.dart';

part 'user.entity.g.dart';
part 'user.entity.migrations.dart';

@OrmEntity(tableName: 'user')
class UserEntity extends Entity<UserEntity, UserEntityMeta>
    with _UserEntityMixin, UserEntityMigrations {

  const UserEntity({
    super.id,
    super.createdAt,
    super.updatedAt,
    this.claims,
    this.uid,
    this.email,
    this.phoneNumber,
    this.displayName,
    this.photoURL,
    this.provider,
  });

  @override
  @column
  final List<String>? claims;

  @override
  @column
  final String? uid;

  @override
  @column
  final String? email;
  @override
  @column
  final String? phoneNumber;
  
  @override
  @column
  final String? displayName;
  
  @override
  @OrmColumn(isEnum: true)
  final OAuthProvider? provider;

  @override
  @column
  final String? photoURL;
}

enum OAuthProvider { google, apple, facebook }

Once you have created or updated your entity files, open terminal and run the following from the root directory of your project:

dart run build_runner build

OrmManager

You need an instance of OrmManager to interact with the storage.
Create an instance of OrmManager as early as possible.

We recommend registering it as a singleton during app start-up using get_it or any DI you prefer.

For example, in your void main() function before runApp(), you can have the following:

final ormManager = OrmManager(
     /// update this version number whenever you update your entities
     /// such as adding new properties/fields.
      dbVersion: 1,
      /// dbEngine defaults to DbEngine.sqflite so you can remove this line if
      // you want to use the default engine
      dbEngine: DbEngine.sqflite,
      dbName: 'your_db_name_here.db',
      tables: <Entity>[
        /// instatiate all your entities that must be saved in db here
        const UserEntity(),
      ],
    );
GetIt.I.registerSingleton(ormManager);

To keep your code clean, we recommend you have the above code in a seperate file. For example in src/orm.init.dart

The dbEngine value defaults to DbEngine.sqflite, and may be one of the following:

  inMemory,
  sqfliteCommon,
  sqflite,
  sharedPreferences,

However, not all engines are available on all platforms. Here is a breakdown of each platform and supported engines:

Andoid: all (we recommend sqflite)
iOS: all (we recommend sqflite)
macOS: all (we recommend sqflite)
Linux: inMemory, sqfliteCommon, sharedPreferences (defaults to sqfliteCommon)
Windows: inMemory, sqfliteCommon, sharedPreferences (defaults to sqfliteCommon)
web: sharedPreferences (defaults to sharedPreferences)

If you provide a dbEngine value not supported by a platform, then the default for that platform is used.

Once your OrmManager is set, you can use it from anywhere in your code. If you are using get_it for example, you can get your storage instance as:

final orm = GetIt.I<OrmManager>();
final {EntityType}Orm storage = orm.getStorage(/* Instance of your Entity here */);

For example, to get storage for UserEntity:

final orm = GetIt.I<OrmManager>();
final UserEntityOrm storage = orm.getStorage(const UserEntity())

IMPORTANT: You NEED to specify type (e.g UserEntityOrm above) for you to get ColumnDefitions on your Filters later. The type class is auto-generated when you run dart run build_runner build

CRUD operations

CRUD - Create

Will throw error if record with same id already exists:

final entity = await storage.insert(
                                UserEntity(id: 'user1',   
                                displayName: 'Test User',
                                ));

We recommend using uuid for generating ids.

You can insertOrUpdate instead, which will update record if it exists:

final entity = await storage.insertOrUpdate(
                                UserEntity(id: 'user1',   
                                displayName: 'Test User',
                                ));

You can insert more than one record at a time:

final entities = await storage.insertList([
                                UserEntity(id: 'user1',   
                                displayName: 'Test User'), 
                                ...,
                                ]);

An equivalent for insertOrUpdate for more that one record exists:

final entities = await storage.insertOrUpdateList([
                                UserEntity(id: 'user1',   
                                displayName: 'Test User'), 
                                ...,
                                ]);

CRUD - Read

Get single record:

final entity = await storage.firstWhereOrNull(...);

More than one record:

final entities = await storage.where(...);

CRUD - Update

You can use the insertOrUpdate options as explained before, which will insert records
if they do not exist. But, if all you want is to strictly update existing records, then:

final updatedCount = await storage.update(where: ...);

CRUD - Delete

final deletedCount = await storage.delete(where: ...);

The Filter function

Most of the queries will need a where parameter which is a function that must return a Filter.
The function has a parameter t which is meta description of your properties as ColumnDefinitions.

Here are some examples:

Get UserEntity with id = 'user1'

final user = await storage.firstWhereOrNull(
      where: (t) => Filter(
        t.id,
        value: 'user1',
      ),
    );

Delete all UserEntitys with uid != null

await storage.delete(
      where: (t) => Filter(
        t.uid,
        condition: OrmCondition.notNull,
      ),
    );

Get all UserEntitys with rating >= 20

final users = await storage.where(
      where: (t) => Filter(
        t.rating,
        condition: OrmCondition.greaterThanOrEqual,
        value: 20,
      ),
    );

Get all UserEntitys with rating between 10 and 100

final users = await storage.where(
      where: (t) => Filter(
        t.rating,
        condition: OrmCondition.between,
        value: 10,
        secondaryValue: 100,
      ),
    );

Chaining and grouping filters

You can have complex filters that meet your needs.
Use utility functions such as startGroup(), endGroup(), filter() and(), and or().

filter() and(), and or() also have parameters openGroup and closeGroup to simplify the grouping so that you may not need startGroup() and endGroup(). However, we recommend using startGroup() and endGroup() since they are easy to read and understand their effects.

Think of grouping as opening and closing brackets, and putting the operations in-between the openGroup...closeGroup into those brackets.

In the example below, the last or() and and() filters will be grouped into (...).

Example:

final users = await storage.where(
      where: (t) => Filter.startGroup()
          .filter(
            t.displayName,
            condition: OrmCondition.like,
            value: '%flu%',
          )
          .and(
            t.rating,
            value: 10,
          )
          .endGroup()
          .or(
            openGroup: true,
            t.displayName,
            value: 'Loveable',
          )
          .and(
            t.rating,
            value: 11002,
            closeGroup: true,
          ),
    );

startGroup() must usually be followed by filter() before chaining additional filters. Remember to endGroup()/closeGroup.

Migrations - Changes to Entity classes and Database updates

If you update any of your Entity classes, you need to run dart run build_runner build again.

If you add/remove @column or any annotated item in your Entity classes then increment OrmManager's dbVersion and add the migrations in the respective {entity_name}.entity.migrations.dart files.

The simplest way to migrate is either to drop and recreate the entity table (losing all data in that table), or specifying the added columns:

Example UserEntity migration: (the file itself is auto-generated the first time you run dart run build_runner build):

mixin UserEntityMigrations on Entity<UserEntity, UserEntityMeta> {
  @override
  bool recreateTableAt(int newVersion) {
    return switch (newVersion) {
        /// when dbVersion = 3, drop and recreate table
        3 => true,
      _ => false,
    };
  }

  @override
  List<ColumnDefinition> addColumnsAt(int newVersion) {
    return switch (newVersion) {
        /// Here we are saying we added property 
        /// named provider when we set dbVersion = 2.
        /// All [@column] properties in your entity class 
        /// are available in [meta] object as [ColumnDefinition]s
      2 => [meta.provider],
      _ => [],
    };
  }
}

In {entity_name}.entity.migrations.dart You can also override downgradeTable() and additionalUpgradeQueries(), returning queries that must be run during that operation.

You can also override onUpgradeComplete and onDowngradeComplete to return custom queries that will be run after completion of upgrade/downgrade.

There is also onCreateComplete which you can return queries that will be run the first time the database is created.

As a reminder, when you update your entity files, run:

dart run build_runner build

Supported data types

• String
• bool
• int
• double
• DateTime
• enums (needs @OrmColumn(isEnum: true) to be specified)
• Custom classes (Objects) - they need to have factory fromMap(map) and function toMap()
• Lists of above types (e.g List<String>)

All entity classes will already have toMap implemented. You need to define the factory fromMap(map) if you want to have the class as a column in another entity.
For convenience, you can call the load() function that will do the rest.

Example factory for UserEntity:

@OrmEntity(tableName: 'user')
class UserEntity extends Entity<UserEntit... {
  
  /// default constructor here

  factory UserEntity.fromMap(map) {
    return const UserEntity().load(map);
  }

  /// rest of the class here
}