dalicious

dalicious

dalicious is a toolkit for your data access layer.

• intuitive transactions and models
• little sugar
• multi-database support in same process

Currently supports:

Postgres
Sql Server

Example

Initializing

var dalicious = require('dalicious');
var Mssql = require('dalicious/mssql');
var Store = Mssql.define({user: 'sa', password: 'secret'});
var Dal = dalicious.define(Store);
var Model = dalicious.Model;

// define your models using prototypical inheritance. Model base can
// be your own class intead of dalicious.Model
function User() {
  Model.apply(this, arguments);
}
util.inherits(User);
User.prototype.create = function(email, cb) {
  this.dao.query({insert: {email: email}, returning: ['id']}).one(cb);
});

// register models
Dal.dal('User', {model: User, table: 'Users'});
Dal.dalify(function(err) {
  // dal is ready for use
});

Using

var dal = new Dal();

// Use your model
dal.User.create(function(err, id) {
  ...
});

// Use low-level data access object (DAO)
dal.store.UserDao.findById(id, function(err, row) {
    ...
});

dal.store.UserDao.query({
  select: ['id', 'name'],
  where: {id: id}
}).all(function(err, rows) {
    ...
});

// Use plain sql
dal
  .sql('select * from Users where createdAt > $1', [new Date('1-9-2013')])
  .all(function(err, rows) {
    ...
  });

// use T-sql (sql server)
dal.store
  .tsql(
    'insert into images (image) output inserted.id values (@buffer)',
    {buffer: buffer}
  )
  .all(function(err, rows) {
    ...
  });

Transactions

var tx = dal.transactable();
var userId;

async.series([
  function(cb) {
    tx.begin(cb)
  },
  function(cb) {
    tx.User.query(...).function(err, id) { userId = id; cb() }
  },
  function(cb) {
    tx.Account.query(...)
  },
  function(cb) {
    tx.sql(...)
  }
], function(err) {
  if (err) return tx.rollback();
  tx.commit();
})

Multi DB

var dalicious = require('dalicious');
var Mssql = require('dalicious/mssql');
var MainDb = Mssql.define({user: 'sa', password: 'secret', database: 'main'});
var ReportDb = Mssql.define({user: 'sa', password: 'secret', database: 'report'});

var Dal = dalicious.define(MainDb);
var dal = new Dal();
var ReportDal = dalicious.define(ReportDb);
var reportDal = new ReportDal();

...

Understanding

Data Access Layer (DAL)

• has a database specific store
• has 1 or more models

Store

• database storage
• has 1 or more data access objects

Model

• encapsulates business logic
• may use one or more Data Access Objects
• may use plain SQL or store-specific dialects (mssql tsql)
• has a default Data Access Object named, this.dao

Data Access Object (DAO)

• 1-1 mapping to table or collection
• data access logic not business logic
• has a schema for inspection