Sequelize(4) 范围

范围（scope）: 定义好范围在后续的操作中可以减少条件的重复，如只选择未删除用户。

跟模型相关的地方都可以添加

// 修改默认所有操作的范围 default Scope
var Project = sequelize.define( 'project', {
    // Attributes
}, {
    defaultScope: {
        where: {
            active: true
        }
    },
    scopes: {
        deleted: {
            where: {
                deleted: true
            }
        },
        activeUsers: {
            include: [
                { model: User, where: { active: true } }
      ]
        }
    }
} );



// 移除默认范围，设置为 deleted 范围
Project.scope( 'deleted' ).findAll();

// 与上面等价
var DeletedProjects = Project.scope( 'deleted' );
DeletedProjects.findAll();

var Post = sequelize.define( 'post', attributes, {
    defaultScope: {
        where: {
            active: true
        }
    },
    scopes: {
        deleted: {
            where: {
                deleted: true
            }
        }
    }
} );

设置联系时，加入范围

User.hasMany( Post ); // regular getPosts association
User.hasMany( Post.scope( 'deleted' ), { as: 'deletedPosts' } );