node-model.js

model.js

model.js is a simple ORM (Object Relational Mapper) for use with Node.js and MySQL.

Requirements

• Node.js
• node-mysql
• MySQL

Usage

Define models

Create a model object by using the model() function. It takes the following arguments:

• tableName - The name of the database table
• fields - A list of field names not including id

It is assumed all tables have a primary key named id of type INT with auto increment.

var User = model('users', ['name', 'email']);

Connect to the database

Use the mysql module to connect to the database.

var mysql = require('mysql');
var db = mysql.createConnection({
  host: 'localhost',
  user: 'username',
  password: 'password',
  database: 'database'
});
db.connect();

Save a row

Use the save() function to save a row into the table. If the row has not been saved before, it will be assigned an id automatically.

var john = new User(db, {name: 'John', email: '[e-mail]'});
john.save(function () {
 
  console.log(john.id);
 
});

Retrieve a row

Use the get() function to retrieve a row from the table. Currently you can only retrieve rows by their id.

var user_id = 1;
var theUser = new User(db, {id: user_id});
theUser.get(function () {
 
  console.log('Your user name: ', theUser.name);
 
});

Access row data

Convert a row into an object literal using the data() function.

var userData = theUser.data(); // {id: 1, name: 'John', email: '[e-mail]'}

Update a row

Use the setData() function to update a row's data.

theUser.setData({name: 'Michael', email: '[e-mail]'});
theUser.save();

Or use a field's property to update a single field.

theUser.name = 'Michael';
theUser.save();

Remove a row

Use the remove() function to delete a row from a table.

var theUser = new User(db, {id: 1});
theUser.remove();

Count rows

Use the count() function to count rows in a table by any equality condition.

User.count(db, {name: 'John'}, function (count) {
 
  console.log('Number of users named John: ', count);
 
});

Define relationships

Define the relationship between model objects using the model.oneToMany() function. It takes the following arguments:

• parentModel - The 'One' in the relationship
• childModel - The 'Many' in the relationship
• parentName - The method name to access the parent from a child
• childrenName - The method name to access the list of children from the parent
• childModelField (optional) - The field name in the child corresponding to the parent id. If not specified, it is assumed to be parentName + _id

var User = model('users', ['name', 'email']);
var Post = model('posts', ['user_id', 'message']);
model.oneToMany(User, Post, 'user', 'posts'); // childModelField becomes user_id

Currently One To Many relationships are the only type of relationship implemented in model.js.

Save related rows

var john = new User(db, {id: 1});
john.get(function () {
 
  var firstPost = new Post(db, {user_id: john.id, message: 'Hello'});
  firstPost.save();
 
});

Retrieve related rows

Get all of a user's posts:

var john = new User(db, {id: 1});
john.get(function () {
 
  john.posts(function (posts) {
  
    for (var i = 0, l = posts.length; i < l; i++) {
      console.log(john.name + ' says: ' + posts[i].message);
    }
  
  });
 
});

Or get the user of a post:

var post = new Post(db, {id: 1});
post.get(function () {
 
  post.user(function (user) {
 
    console.log(user.name + ' says: ' + post.message);
 
  });
 
});