From 54feaca70f77b39093fe417dcd89eb7c74930e2e Mon Sep 17 00:00:00 2001 From: Russell Keith-Magee Date: Thu, 25 Jan 2007 13:47:55 +0000 Subject: [PATCH] Fixed #3098 -- Added db_table parameter to m2m fields, allowing the specification of a custom table name for the m2m table. Thanks, Wolfram Kriesing. git-svn-id: http://code.djangoproject.com/svn/django/trunk@4429 bcc190cf-cafb-0310-a4f2-bffc1f526a37 --- django/db/models/fields/related.py | 6 +- docs/model-api.txt | 4 + tests/modeltests/custom_columns/models.py | 94 ++++++++++++++++++----- 3 files changed, 82 insertions(+), 22 deletions(-) diff --git a/django/db/models/fields/related.py b/django/db/models/fields/related.py index ef5432686b..7c373792b2 100644 --- a/django/db/models/fields/related.py +++ b/django/db/models/fields/related.py @@ -629,6 +629,7 @@ class ManyToManyField(RelatedField, Field): limit_choices_to=kwargs.pop('limit_choices_to', None), raw_id_admin=kwargs.pop('raw_id_admin', False), symmetrical=kwargs.pop('symmetrical', True)) + self.db_table = kwargs.pop('db_table', None) if kwargs["rel"].raw_id_admin: kwargs.setdefault("validator_list", []).append(self.isValidIDList) Field.__init__(self, **kwargs) @@ -651,7 +652,10 @@ class ManyToManyField(RelatedField, Field): def _get_m2m_db_table(self, opts): "Function that can be curried to provide the m2m table name for this relation" - return '%s_%s' % (opts.db_table, self.name) + if self.db_table: + return self.db_table + else: + return '%s_%s' % (opts.db_table, self.name) def _get_m2m_column_name(self, related): "Function that can be curried to provide the source column name for the m2m table" diff --git a/docs/model-api.txt b/docs/model-api.txt index 33742220a3..8abd88f7ec 100644 --- a/docs/model-api.txt +++ b/docs/model-api.txt @@ -874,6 +874,10 @@ the relationship should work. All are optional: force Django to add the descriptor for the reverse relationship, allowing ``ManyToMany`` relationships to be non-symmetrical. + + ``db_table`` The name of the table to create for storing the many-to-many + data. If this is not provided, Django will assume a default + name based upon the names of the two tables being joined. ======================= ============================================================ diff --git a/tests/modeltests/custom_columns/models.py b/tests/modeltests/custom_columns/models.py index e88fa80da2..c09ca05557 100644 --- a/tests/modeltests/custom_columns/models.py +++ b/tests/modeltests/custom_columns/models.py @@ -1,53 +1,105 @@ """ -17. Custom column names +17. Custom column/table names If your database column name is different than your model attribute, use the ``db_column`` parameter. Note that you'll use the field's name, not its column name, in API usage. + +If your database table name is different than your model name, use the +``db_table`` Meta attribute. This has no effect on the API used to +query the database. + +If you need to use a table name for a many-to-many relationship that differs +from the default generated name, use the ``db_table`` parameter on the +ManyToMany field. This has no effect on the API for querying the database. + """ from django.db import models -class Person(models.Model): +class Author(models.Model): first_name = models.CharField(maxlength=30, db_column='firstname') last_name = models.CharField(maxlength=30, db_column='last') def __str__(self): return '%s %s' % (self.first_name, self.last_name) -__test__ = {'API_TESTS':""" -# Create a Person. ->>> p = Person(first_name='John', last_name='Smith') ->>> p.save() + class Meta: + db_table = 'my_author_table' + ordering = ('last_name','first_name') ->>> p.id +class Article(models.Model): + headline = models.CharField(maxlength=100) + authors = models.ManyToManyField(Author, db_table='my_m2m_table') + + def __str__(self): + return self.headline + + class Meta: + ordering = ('headline',) + +__test__ = {'API_TESTS':""" +# Create a Author. +>>> a = Author(first_name='John', last_name='Smith') +>>> a.save() + +>>> a.id 1 ->>> Person.objects.all() -[] +# Create another author +>>> a2 = Author(first_name='Peter', last_name='Jones') +>>> a2.save() ->>> Person.objects.filter(first_name__exact='John') -[] +# Create an article +>>> art = Article(headline='Django lets you build web apps easily') +>>> art.save() +>>> art.authors = [a, a2] ->>> Person.objects.get(first_name__exact='John') - +# Although the table and column names on Author have been set to +# custom values, nothing about using the Author model has changed... ->>> Person.objects.filter(firstname__exact='John') +# Query the available authors +>>> Author.objects.all() +[, ] + +>>> Author.objects.filter(first_name__exact='John') +[] + +>>> Author.objects.get(first_name__exact='John') + + +>>> Author.objects.filter(firstname__exact='John') Traceback (most recent call last): ... TypeError: Cannot resolve keyword 'firstname' into field ->>> p = Person.objects.get(last_name__exact='Smith') ->>> p.first_name +>>> a = Author.objects.get(last_name__exact='Smith') +>>> a.first_name 'John' ->>> p.last_name +>>> a.last_name 'Smith' ->>> p.firstname +>>> a.firstname Traceback (most recent call last): ... -AttributeError: 'Person' object has no attribute 'firstname' ->>> p.last +AttributeError: 'Author' object has no attribute 'firstname' +>>> a.last Traceback (most recent call last): ... -AttributeError: 'Person' object has no attribute 'last' +AttributeError: 'Author' object has no attribute 'last' + +# Although the Article table uses a custom m2m table, +# nothing about using the m2m relationship has changed... + +# Get all the authors for an article +>>> art.authors.all() +[, ] + +# Get the articles for an author +>>> a.article_set.all() +[] + +# Query the authors across the m2m relation +>>> art.authors.filter(last_name='Jones') +[] + """}