zmsmith

from mongoengine.document import Document, EmbeddedDocument

class DecisionDocument(EmbeddedDocument):

    guilt = fields.StringField(required=True)
    details = fields.DictField()
    
    meta = {'allow_inheritance': False}

zmsmith

{
	"_id" : {
		"set" : ISODate("2012-02-08T18:37:52.191Z"),
		"db_key" : "_id"
	},
	"judge" : {
		"set" : ISODate("2012-02-08T18:37:52.191Z"),
		"db_key" : "j"
	},
	"decision" : {

zmsmith

{
	"_id" : {
		"set" : ISODate("2012-02-08T18:37:52.191Z"),
		"db_key" : "_id"
	},
	"decision" : {
		"set" : ISODate("2012-02-08T18:37:52.191Z"),
		"db_key" : "d",
		"embedded_fields" : {
			"guilt" : {

zmsmith

from test.app import DecisionDocument, TrialDocument

subdoc = DecisionDocument(guilt='definitely', details={'bad_person_score': 'Very Bad Man'})
doc = TrialDocument(decision=[subdoc], reporter='Tom', jury='peers')
doc.save()

# -----Object Created------

{
	"_id" : ObjectId("4f32c2f4d0ba3a4b5e000000"),

zmsmith

from mongoengine.base import TopLevelDocumentMetaclass

class CompressedKeyDocumentMetaclass(TopLevelDocumentMetaclass):

    def __new__(cls, name, bases, attrs):
        """
        MongoEngine Document Classes access the 'TopLevelDocumentMetaclass'
        __metaclass__. We allow that metaclass to set attrs on the class 
        and then compress the fields in the event that the instantiated
        Document Class contains the meta attr 'compress_keys'

zmsmith

{
	"_id" : ObjectId("4f15adc6e9f3d887f2ba7a31"),
	"uid" : 274790,
	"did" : 720717,
	"city_id" : 4,
	"score" : 10000,
	"published" : ISODate("2012-01-17T17:20:54Z"),
	"active" : true,
	"recs" : [
		{

zmsmith

from django.db import models

class Author(models.Model):
    first_name = models.CharField(max_length=255)
    last_name = models.CharField(max_length=255)
    books = models.ManyToManyField('Book')

class Book(models.Model):
    title = models.CharField(max_length=255)

zmsmith

book_store = BookStore.objects.get(name="B&N")
authors = Author.objects.filter(book__in=book_store.books.all())

zmsmith

from django.db.models.fields.related import ReverseManyRelatedObjectsDescriptor
from django.db.models import ManyToManyField

class NewReverseManyRelatedObjectsDescriptor(ReverseManyRelatedObjectsDescriptor):

    def make_id_list(self, obj):

        through = self.field.rel.through
        name = self.field.m2m_field_name()
        related_name =self.field.m2m_reverse_field_name()

zmsmith

SELECT `author`.`id`, `author`.`first_name`, `author`.`last_name`
FROM `author`
INNER JOIN `author_books`
ON (`author`.`id` = `author_books`.`author_id`)
 WHERE `author_books`.`book_id`
IN (SELECT U0.`book_id` FROM `bookstore_books` U0 WHERE U0.`bookstore_id` = 1 )