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	backwards compatible for all practical purposes. Fixed #2391, #2489, #2996, #3322, #3344, #3370, #3406, #3432, #3454, #3492, #3582, #3690, #3878, #3891, #3937, #4039, #4141, #4227, #4286, #4291, #4300, #4452, #4702 git-svn-id: http://code.djangoproject.com/svn/django/trunk@5609 bcc190cf-cafb-0310-a4f2-bffc1f526a37
		
			
				
	
	
		
			96 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			96 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| """
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| 14. Using a custom primary key
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| 
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| By default, Django adds an ``"id"`` field to each model. But you can override
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| this behavior by explicitly adding ``primary_key=True`` to a field.
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| """
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| 
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| from django.db import models
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| 
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| class Employee(models.Model):
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|     employee_code = models.CharField(maxlength=10, primary_key=True,
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|             db_column = 'code')
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|     first_name = models.CharField(maxlength=20)
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|     last_name = models.CharField(maxlength=20)
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|     class Meta:
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|         ordering = ('last_name', 'first_name')
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| 
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|     def __unicode__(self):
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|         return u"%s %s" % (self.first_name, self.last_name)
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| 
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| class Business(models.Model):
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|     name = models.CharField(maxlength=20, primary_key=True)
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|     employees = models.ManyToManyField(Employee)
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|     class Meta:
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|         verbose_name_plural = 'businesses'
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| 
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|     def __unicode__(self):
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|         return self.name
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| 
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| __test__ = {'API_TESTS':"""
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| >>> dan = Employee(employee_code='ABC123', first_name='Dan', last_name='Jones')
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| >>> dan.save()
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| >>> Employee.objects.all()
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| [<Employee: Dan Jones>]
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| 
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| >>> fran = Employee(employee_code='XYZ456', first_name='Fran', last_name='Bones')
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| >>> fran.save()
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| >>> Employee.objects.all()
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| [<Employee: Fran Bones>, <Employee: Dan Jones>]
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| 
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| >>> Employee.objects.get(pk='ABC123')
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| <Employee: Dan Jones>
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| >>> Employee.objects.get(pk='XYZ456')
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| <Employee: Fran Bones>
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| >>> Employee.objects.get(pk='foo')
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| Traceback (most recent call last):
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|     ...
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| DoesNotExist: Employee matching query does not exist.
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| 
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| # Use the name of the primary key, rather than pk.
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| >>> Employee.objects.get(employee_code__exact='ABC123')
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| <Employee: Dan Jones>
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| 
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| # pk can be used as a substitute for the primary key.
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| >>> Employee.objects.filter(pk__in=['ABC123','XYZ456'])
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| [<Employee: Fran Bones>, <Employee: Dan Jones>]
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| 
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| # Fran got married and changed her last name.
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| >>> fran = Employee.objects.get(pk='XYZ456')
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| >>> fran.last_name = 'Jones'
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| >>> fran.save()
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| >>> Employee.objects.filter(last_name__exact='Jones')
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| [<Employee: Dan Jones>, <Employee: Fran Jones>]
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| >>> Employee.objects.in_bulk(['ABC123', 'XYZ456'])
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| {u'XYZ456': <Employee: Fran Jones>, u'ABC123': <Employee: Dan Jones>}
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| 
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| >>> b = Business(name='Sears')
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| >>> b.save()
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| >>> b.employees.add(dan, fran)
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| >>> b.employees.all()
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| [<Employee: Dan Jones>, <Employee: Fran Jones>]
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| >>> fran.business_set.all()
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| [<Business: Sears>]
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| >>> Business.objects.in_bulk(['Sears'])
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| {u'Sears': <Business: Sears>}
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| 
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| >>> Business.objects.filter(name__exact='Sears')
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| [<Business: Sears>]
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| >>> Business.objects.filter(pk='Sears')
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| [<Business: Sears>]
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| 
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| # Queries across tables, involving primary key
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| >>> Employee.objects.filter(business__name__exact='Sears')
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| [<Employee: Dan Jones>, <Employee: Fran Jones>]
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| >>> Employee.objects.filter(business__pk='Sears')
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| [<Employee: Dan Jones>, <Employee: Fran Jones>]
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| 
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| >>> Business.objects.filter(employees__employee_code__exact='ABC123')
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| [<Business: Sears>]
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| >>> Business.objects.filter(employees__pk='ABC123')
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| [<Business: Sears>]
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| >>> Business.objects.filter(employees__first_name__startswith='Fran')
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| [<Business: Sears>]
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| 
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| """}
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