Early API for a client database abstraction I'm writing, taking cues from the way Django's ORM works.

gistfile1.coffee

# Start a new database with name "testDB" and version 20

window.db = new JohoDB "testDB", 20

# Define the database schema, early days so the relations don't do anything yet, but I'm getting there.

db.addSchema 'Household', {
  id: {type: "int", primaryKey: true, autoIncrement: true}
  address: {type: "string", required: true}
  suburb: {type: "string", required: true}
  postCode: {type: "string", required: true}
}
  
db.addSchema 'People', {
  id: {type: "int", primaryKey: true, autoIncrement: true}
  firstName: {type: "string", required: true}
  lastName: {type: "string", required: true}
  dateOfBirth: {type: "datetime", required: true}
  home: {type: "fk", relation: "Household", relatedName: "occupants"}
  bio: {type: "string"}
  pets: {type: "m2m", relation: "Pets", relatedName: "owners"}
}

db.addSchema 'Pets', {
  id: {type: "int", primaryKey: true, autoIncrement: true}
  name: {type: "string", required: true}
  age: {type: "int"}
}

# Create the database as an IndexedDB, (webSQL is in the plans too), clobber option means it will just destroy whatever is there, for testing

db.initDB "indexedDb", clobber: true

# Creating an array of functions to make the execution of promises sequential.

# Each save action, when done without the primary key, will automatically find the nnext available key. Of course this only works because
# the actions are being done sequentially via promises, otherwise it would be a mess. I believe
# in Async often the better solution will be to use a hashed string as an ID, with enough seeding to avoid collisions.

saves = [
  ->
    db.models.Household.save {
      address: "8/17 Churchill Ave"
      suburb: "Sandy Bay"
      postCode: "7005"
    }
  ->
    db.models.Household.save {
      address: "9 Monterey Sq"
      suburb: "Kingston"
      postCode: "7532"
    }
  ->
    db.models.Household.save {
      address: "11 Malamar Place"
      suburb: "Glenorchy"
      postCode: "7023"
    }
  ->
    db.models.People.save {
      firstName: "James"
      lastName: "Rakich"
      dateOfBirth: new Date(1925, 10, 8)
    }
  ->
    db.models.People.save {
      firstName: "Joe"
      lastName: "Bloggs"
      dateOfBirth: new Date(1942, 2, 1)
      bio: "Top bloke here."
    }
  ->
    db.models.Household.query().all().evaluate()
  (result) ->
    console.log 'Household.query().all()', result
  ->
    db.models.Household.query().filter({postCode__gte: "7005"}).evaluate()
  (result) ->
    console.log 'Household.query().filter({postCode__gte: "7005"})', result
  ->
    db.models.Household.query().filter({postCode__gt: "7005"}).evaluate()
  (result) ->
    console.log 'Household.query().filter({postCode__gt: "7005"})', result
  ->
    db.models.Household.query().filter({postCode__gt: "7005"})
                               .exclude({suburb: "Kingston"}).evaluate()
  (result) ->
    console.log 'Household.query().filter({postCode__gt: "7005"}).exclude({suburb: "Kingston"})', result
]

# Iterating over the array here.

result = Q.resolve(true)
for save in saves
  result = result.then save