JugglingDB跨数据库的 ORM 框架

JugglingDB 是一个跨数据库的 ORM 框架，提供了访问大多数数据库的通用接口，支持包括：mysql, mongodb, redis, neo4j and js-memory-storage. 你可扩展其他数据库的适配器，支持回调和钩子。

示例代码：

var Schema = require('./jugglingdb').Schema;
var schema = new Schema('redis', {port: 6379}); //port number depends on your configuration
// define models
var Post = schema.define('Post', {
    title:     { type: String, length: 255 },
    content:   { type: Schema.Text },
    date:      { type: Date,    default: Date.now },
    published: { type: Boolean, default: false }
});
// simplier way to describe model
var User = schema.define('User', {
    name:         String,
    bio:          Schema.Text,
    approved:     Boolean,
    joinedAt:     Date,
    age:          Number
});

// setup relationships
User.hasMany(Post,   {as: 'posts',  foreignKey: 'userId'});
// creates instance methods:
// user.posts(conds)
// user.posts.build(data) // like new Post({userId: user.id});
// user.posts.create(data) // build and save

Post.belongsTo(User, {as: 'author', foreignKey: 'userId'});
// creates instance methods:
// post.author(callback) -- getter when called with function
// post.author() -- sync getter when called without params
// post.author(user) -- setter when called with object

schema.automigrate(); // required only for mysql NOTE: it will drop User and Post tables

// work with models:
var user = new User;
user.save(function (err) {
    var post = user.posts.build({title: 'Hello world'});
    post.save(console.log);
});

// or just call it as function (with the same result):
var user = User();
user.save(...);

// Common API methods

// just instantiate model
new Post
// save model (of course async)
Post.create(cb);
// all posts
Post.all(cb)
// all posts by user
Post.all({where: {userId: user.id}, order: 'id', limit: 10, skip: 20});
// the same as prev
user.posts(cb)
// same as new Post({userId: user.id});
user.posts.build
// save as Post.create({userId: user.id}, cb);
user.posts.create(cb)
// find instance by id
User.find(1, cb)
// count instances
User.count([conditions, ]cb)
// destroy instance
user.destroy(cb);
// destroy all instances
User.destroyAll(cb);

// Setup validations
User.validatesPresenceOf('name', 'email')
User.validatesLengthOf('password', {min: 5, message: {min: 'Password is too short'}});
User.validatesInclusionOf('gender', {in: ['male', 'female']});
User.validatesExclusionOf('domain', {in: ['www', 'billing', 'admin']});
User.validatesNumericalityOf('age', {int: true});
User.validatesUniquenessOf('email', {message: 'email is not unique'});

user.isValid(function (valid) {
    if (!valid) {
        user.errors // hash of errors {attr: [errmessage, errmessage, ...], attr: ...}    
    }
})