使用旧表

虽然开箱即用的 Sequelize 似乎有点有态度，但通过定义（否则生成的）表和字段名称，可以轻松处理旧表并向前证明你的应用。

¥While out of the box Sequelize will seem a bit opinionated it's easy to work legacy tables and forward proof your application by defining (otherwise generated) table and field names.

表

¥Tables

class User extends Model {}
User.init({
  // ...
}, {
  modelName: 'user',
  tableName: 'users',
  sequelize,
});

字段

¥Fields

class MyModel extends Model {}
MyModel.init({
  userId: {
    type: DataTypes.INTEGER,
    field: 'user_id'
  }
}, { sequelize });

主键

¥Primary keys

默认情况下，Sequelize 会假设你的表具有 id 主键属性。

¥Sequelize will assume your table has a id primary key property by default.

要定义你自己的主键：

¥To define your own primary key:

class Collection extends Model {}
Collection.init({
  uid: {
    type: DataTypes.INTEGER,
    primaryKey: true,
    autoIncrement: true // Automatically gets converted to SERIAL for postgres
  }
}, { sequelize });

class Collection extends Model {}
Collection.init({
  uuid: {
    type: DataTypes.UUID,
    primaryKey: true
  }
}, { sequelize });

如果你的模型根本没有主键，你可以使用 Model.removeAttribute('id');

¥And if your model has no primary key at all you can use Model.removeAttribute('id');

没有主键的实例仍然可以使用 Model.findOne 和 Model.findAll 检索。虽然目前可以使用它们的实例方法（instance.save、instance.update 等），但这样做会导致细微的错误，并计划在未来的重大更新中删除。

¥Instances without primary keys can still be retrieved using Model.findOne and Model.findAll.\ While it's currently possible to use their instance methods (instance.save, instance.update, etc…), doing this will lead to subtle bugs, and is planned for removal in a future major update.

信息

如果你的模型没有主键，则需要使用以下实例方法的静态等效项，并提供你自己的 where 参数：

¥If your model has no primary keys, you need to use the static equivalent of the following instance methods, and provide your own where parameter:

• instance.save：Model.update

• instance.update：Model.update

• instance.reload：Model.findOne

• instance.destroy：Model.destroy

• instance.restore：Model.restore

• instance.decrement：Model.decrement

• instance.increment：Model.increment

外键

¥Foreign keys

// 1:1
Organization.belongsTo(User, { foreignKey: 'owner_id' });
User.hasOne(Organization, { foreignKey: 'owner_id' });

// 1:M
Project.hasMany(Task, { foreignKey: 'tasks_pk' });
Task.belongsTo(Project, { foreignKey: 'tasks_pk' });

// N:M
User.belongsToMany(Role, { through: 'user_has_roles', foreignKey: 'user_role_user_id' });
Role.belongsToMany(User, { through: 'user_has_roles', foreignKey: 'roles_identifier' });