#FastLegS

PostgreSQL ORM on top of node-postgres.

##Installation

npm install FastLegS

##Quickstart

NOTE: As of version0.2.0, both PostgreSQL and MySQL are supported. You indicate which database you are using at object instantiation time. All other operations and interfaces behave the same as older versions.

Setup for versions < 0.2.0

var FastLegS = require('FastLegS');
...
FastLegS.connect(connectionParams);
...

Setup for versions >= 0.2.0

MySQL:

var FastLegSBase = require('FastLegS');
var FastLegS = new FastLegSBase('mysql');
...
FastLegS.connect(connectionParams);
...

PostgreSQL:

var FastLegSBase = require('FastLegS');
var FastLegS = new FastLegSBase('pg');
...
FastLegS.connect(connectionParams);
...

Example:

var FastLegSBase = require('FastLegS');

// gonna use PostgreSQL
var FastLegS = new FastLegSBase('pg');

var connectionParams = {
  user: 'shes'
, password: 'got'
, database: 'legs'
, host: 'localhost'
, port: 5432
}

FastLegS.connect(connectionParams);

var Post = FastLegS.Base.extend({
  tableName: 'posts',
  primaryKey: 'id'
});

Post.create(
  { title: 'Some Title 1', body: 'Some body 1' }, 
  function(err, results) {
    Post.find(
      { 'title.ilike': '%title%' }, 
      { only: ['id', 'body'] }, 
      function(err, post) {
        // Hooray!
      }
    );
  }
);

#The Full Monty

The following examples use these database tables as examples:

posts

id	title	blurb	body	published
1	Some Title 1	Some blurb 1	Some body 1	false
2	Some Title 1	Some blurb 2	Some body 2	true
3	Some Title 1	Some blurb 3	Some body 3	false
4	Some Title 1	Some blurb 4	Some body 4	true

comments

id	post_id	comment	created_at
1	1	Comment 1	2012-12-11
2	1	Comment 2	2012-12-11
3	2	Comment 3	2012-12-11
4	2	Comment 4	2012-12-11
5	3	Comment 5	2012-12-11
6	3	Comment 6	2012-12-11
7	4	Comment 7	2012-12-11
8	4	Comment 8	2012-12-11

Given this setup:

var FastLegSBase = require('FastLegS');

// gonna use PostgreSQL
var FastLegS = new FastLegSBase('pg');

var connectionParams = {
  user: 'shes', password: 'got',
  database: 'legs', host: 'localhost', port: 5432
}

FastLegS.connect(connectionParams);

var callback = function(err, results) {
  console.dir(err);
  console.dir(results);
}

var Comment = FastLegS.Base.extend({
  tableName: 'comments',
  primaryKey: 'id'
});

var Post = FastLegS.Base.extend({
  tableName: 'posts',
  primaryKey: 'id'
});

The following are examples of basic CRUD operations:

##Create

Calls to create can take an object or an array of objects.

Post.create(
  { id: 5, title: 'Some Title 5', body: 'Some body 5' },
  callback
)

Post.create(
  [{ id: 6, title: 'Some Title 6', body: 'Some body 6' },
   { id: 7, title: 'Some Title 7', body: 'Some body 7' }],
  callback
)

The results passed to the callback are different depending on the database.

In the case of PostgreSQL, the results will be an object of the form:

{
  rows: [{ id: 5,
         title: 'Some Title 5',
         blurb: null,
         body: 'Some body 5',
         published: null }],
  command: INSERT,
  rowCount: 1,
  oid: 0
}

In the case of MySQL, the results will be an object of the form:

{
  fieldCount: 0,
  affectedRows: 1,
  insertId: 0,
  serverStatus: 2,
  warningCount: 0,
  message: ''
}

##Read

The various forms of the find command are very flexible. We'll present a few of them here.

####All:

Post.find({}, callback)

outputs:

[ 
  { id: 1,
    title: 'Some Title 1',
    blurb: null,
    body: 'Some body 1',
    published: null,
    created_at: null,
    updated_at: null },
  ...
  { id: 5,
    title: 'Some Title 5',
    blurb: null,
    body: 'Some body 5',
    published: null,
    created_at: null,
    updated_at: null },
  { id: 6,
    title: 'Some Title 6',
    blurb: null,
    body: 'Some body 6',
    published: null,
    created_at: null,
    updated_at: null },
  { id: 7,
    title: 'Some Title 7',
    blurb: null,
    body: 'Some body 7',
    published: null,
    created_at: null,
    updated_at: null } 
]

####By primary key:

Post.find(6, callback)

outputs:

{
  id: 6,
  title: 'Some Title 6',
  blurb: null,
  body: 'Some body 6',
  published: null,
  created_at: null,
  updated_at: null
}

####Only show some fields:

Post.find(6, {only: ['id','title']}, callback)

outputs:

{ id: 6, title: 'Some Title 6' }

####Some clauses:

Post.find({'title.like': 'Some%'}, callback)
Post.find({'id.in': [6, 7]}, callback)
Post.find({'id.nin': [6]}, callback)
Post.find({'$or': {'id.equals': 5, 'body.like': '%body 7'}}, callback)

####Order, offset, limit

Post.find({}, { order: ['-id'] }, callback)
Post.find({}, { offset: 1, limit: 1 }, callback)

####Count:

Post.find({}, {count: true}, callback)

outputs:

{ count: 7 }

##Update

Post.update(
  { title: 'Some Title 6' },
  { title: 'Renamed title' },
  callback
)

##Delete

Post.destroy({ 'id.in': [5, 7]}, callback)
Post.truncate(callback)

##A Taste of Relationships

You can call out relationships when you extend FastLegS.Base:

var Post = FastLegS.Base.extend({
  tableName: 'posts',
  primaryKey: 'id',
  many: [
    { 'comments': Comment, joinOn: 'post_id' }
  ]
});

You can then create complex object relationships with join logic:

Post.find(
  {}, 
  { include: { comments: { only: ['id', 'comment'] } } },
  callback
)

outputs:

[
  {
      body: 'Some body 1',
      title: 'Some Title 1',
      id: 1,
      updated_at: null,
      published: false,
      blurb: 'Some blurb 1',
      created_at: null,
      comments: [
          { id: 1, comment: 'Comment 1' },
          { id: 2, comment: 'Comment 2' }
      ]
  },
  {
      body: 'Some body 2',
      title: 'Some Title 2',
      id: 2,
      updated_at: null,
      published: true,
      blurb: null,
      created_at: null,
      comments: [
          { id: 3, comment: 'Comment 3' },
          { id: 4, comment: 'Comment 4' }
      ]
  },
  ...
]

Here's a many-to-many example based on these tables:

students

id	name
1	Abe
2	Ben
3	Christine
4	Delia
5	Egwene

professors

id	name
6	Felix
7	Garret
8	Horton
9	Irene
10	Jane

student_professor

student_id	professor_id
1	6
2	6
3	7
4	7
5	8
1	8
2	9
3	9
4	10
5	10

var Student = FastLegS.Base.extend({
  tableName: 'students',
  primaryKey: 'id',
});

var Professor = FastLegS.Base.extend({
  tableName: 'professors',
  primaryKey: 'id',
})

var StudentProfessor = FastLegS.Base.extend({
  tableName: 'student_professor',
  foreignKeys: [
     { model: Student, key: 'student_id' },
     { model: Professor, key: 'professor_id' }
  ]
})

Student.many = [{
  professors: Professor,
  assoc: StudentProfessor
}]

Professor.many = [{
  students: Student,
  assoc: StudentProfessor
}]

Professor.findOne(
  9,
  {include: { students: {} }},
  function(err, result) {
    inspect(result)
  }
)

outputs:

{
  id: 9,
  name: 'Irene',
  students: [
      { id: 2, name: 'Ben' },
      { id: 3, name: 'Christine' }
  ]
}

This shows that professor Irene has students Ben and Christine

##Summary

The tests are an excellent reference for the various modifiers and syntactic sugar you can use in FastLegS.

##ToDo

Right now, the codebase is split because of syntactic differences between PostgreSQL and MySQL. There is a lot of duplicated code, however. Future versions should abstract out the differences and merge the duplicated code.

Watch for updates to examples in the near future to show features like relationships and advanced queries.

#Contributors

• Micah Silverman (dogeared)
• Thad Clay (thadclay)
• Jan Paul Erkelens (jperkelens)
• Rob Malko (malkomalko)
• Jim Drannbauer (excellentdrums)