nodejs的跨數據庫ORM框架:JugglingDB
JugglingDB為nodejs提供了一個跨數據庫的ORM框架,通過一個共同的接口來訪問大部分流行的數據庫。當前支持:mysql, sqlite3, postgres, couchdb, mongodb, redis, neo4j 和js-memory-storage (yep, 自寫的引擎僅用于測試使用)。你可以為沒有支持的數據庫添加適配器。可以模仿已有的例子編寫,超級簡單。
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, index: true }
});
// simplier way to describe model
var User = schema.define('User', {
name: String,
bio: Schema.Text,
approved: Boolean,
joinedAt: Date,
age: Number
}, {
restPath: '/users' // tell WebService adapter which path use as API endpoint
});
// define any custom method
User.prototype.getNameAndAge = function () {
return this.name + ', ' + this.age;
};
// models also accessible in schema:
schema.models.User;
schema.models.Post;
// 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)
// get one latest post
Post.findOne({where: {published: true}, order: 'date DESC'}, 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: ...}
}
})
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