jaguar_orm

Description:

jaguar orm

jaguar_orm #
Source-generated ORM with relations (one-to-one, one-to-many, many-to-many),
preloading, cascading, polymorphic relations, etc
Features #

Relationships

One To One
One To Many
Many To Many


Preloads
Cascading

Cascaded inserts
Cascaded updates
Cascaded removals


Migration
Polymorphic relations
Composite primary keys
Composite foreign keys

Getting started #
Declaring the Model #
class User {
@PrimaryKey()
String id;

String name;

static const String tableName = '_user';

String toString() => "User($id, $name)";
}
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Declaring the Bean #
A Bean performs database actions on behalf of the model. In this case,
UserBean performs actions for User model. Much of the Bean's
functionality will be source generated.
@GenBean()
class UserBean extends Bean<User> with _UserBean {
UserBean(Adapter adapter) : super(adapter);
}
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Generating Bean logic #
jaguar_orm use source_gen and jaguar_orm_gen to generate bean logic
from bean specification.
Add the following dependencies to dev_dependencies.
build_runner:
jaguar_orm_gen:
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Run the following command to generate Bean logic:
pub run build_runner build
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Connecting to database #
We will use PostgreSQL for this tutorial. PgAdapter is found in the
package jaguar_query_postgres.
final PgAdapter _adapter =
new PgAdapter('example', username: 'postgres', password: 'dart_jaguar');
await _adapter.connect();
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Creating instance of bean #
Beans internally use jaguar_query's Adapter interface to talk to
database. Lets create an instance of UserBean.
final userBean = new UserBean(_adapter);
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Dropping the table #
await userBean.drop();
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Creating a table #
await userBean.createTable();

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Inserting a new record #
await userBean.insert(new User()
..id = '1'
..name = 'teja');
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Fetching record by primary key #
User user = await userBean.find('1');
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Fetching all records #
List<User> users = await userBean.getAll();
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Updating a record #
User user = await userBean.find('1');
user.name = 'teja hackborn';
await userBean.update(user);
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Remove by id #
await userBean.remove('1');
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Remove all #
await userBean.removeAll();
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Examples #
One-To-One example #
class User {
@PrimaryKey()
String id;

String name;

@HasOne(AddressBean)
Address address;

static const String tableName = '_user';

String toString() => "User($id, $name, $address)";
}

class Address {
@PrimaryKey()
String id;

@BelongsTo(UserBean)
String userId;

String street;

static String tableName = 'address';

String toString() => "Post($id, $userId, $street)";
}

@GenBean()
class UserBean extends Bean<User> with _UserBean {
UserBean(Adapter adapter)
: addressBean = new AddressBean(adapter),
super(adapter);

final AddressBean addressBean;

Future createTable() {
final st = Sql
.create(tableName)
.addStr('id', primary: true, length: 50)
.addStr('name', length: 50);
return execCreateTable(st);
}
}

@GenBean()
class AddressBean extends Bean<Address> with _AddressBean {
AddressBean(Adapter adapter) : super(adapter);

Future createTable() {
final st = Sql
.create(tableName)
.addStr('id', primary: true, length: 50)
.addStr('street', length: 150)
.addStr('user_id', length: 50, foreignTable: '_user', foreignCol: 'id');
return execCreateTable(st);
}
}

/// The adapter
PgAdapter _adapter =
new PgAdapter('postgres://postgres:dart_jaguar@localhost/example');

main() async {
// Connect to database
await _adapter.connect();

// Create beans
final userBean = new UserBean(_adapter);
final addressBean = new AddressBean(_adapter);

// Drop old tables
await addressBean.drop();
await userBean.drop();

// Create new tables
await userBean.createTable();
await addressBean.createTable();

// Cascaded One-To-One insert
{
final user = new User()
..id = '1'
..name = 'Teja'
..address = (new Address()
..id = '1'
..street = 'Stockholm');
await userBean.insert(user, cascade: true);
}

// Fetch One-To-One preloaded
{
final user = await userBean.find('1', preload: true);
print(user);
}

// Manual One-To-One insert
{
User user = new User()
..id = '2'
..name = 'Kleak';
await userBean.insert(user, cascade: true);

user = await userBean.find('2');

final address = new Address()
..id = '2'
..street = 'Stockholm';
addressBean.associateUser(address, user);
await addressBean.insert(address);
}

// Manual One-To-One preload
{
final user = await userBean.find('2');
print(user);
user.address = await addressBean.findByUser(user.id);
print(user);
}

// Preload many
{
final users = await userBean.getAll();
print(users);
await userBean.preloadAll(users);
print(users);
}

// Cascaded One-To-One update
{
User user = await userBean.find('1', preload: true);
user.name = 'Teja Hackborn';
user.address.street = 'Stockholm, Sweden';
await userBean.update(user, cascade: true);
}

// Fetch One-To-One relationship preloaded
{
final user = await userBean.find('1', preload: true);
print(user);
}

// Cascaded removal of One-To-One relation
await userBean.remove('1', true);

// Remove addresses belonging to a User
await addressBean.removeByUser('2');

exit(0);
}
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