2016-08-23 119 views
0

這是我的models.py樣子:Django的 - UNIQUE約束失敗的錯誤

from django.db import models 
    from django.core.validators import RegexValidator 

    # Create your models here. 
    class Customer(models.Model): 
     customer_id = models.AutoField(primary_key=True,unique=True) 
     full_name = models.CharField(max_length=50) 
     user_email = models.EmailField(max_length=50) 
     user_pass = models.CharField(max_length=30) 

     def __str__(self): 
      return "%s" % self.full_name 

    class CustomerDetail(models.Model): 
     phone_regex = RegexValidator(regex = r'^\d{10}$', message = "Invalid format! E.g. 4088385778") 
     date_regex = RegexValidator(regex = r'\d{2}[-/]\d{2}[-/]\d{2}', message = "Invalid format! E.g. 05/16/91") 

     address = models.CharField(max_length=100) 
     date_of_birth = models.CharField(validators = [date_regex], max_length = 10, blank = True) 
     company = models.CharField(max_length=30) 
     home_phone = models.CharField(validators = [phone_regex], max_length = 10, blank = True) 
     work_phone = models.CharField(validators = [phone_regex], max_length = 10, blank = True) 
     customer_id = models.ForeignKey(Customer, on_delete=models.CASCADE) 

我加customer_idCustomer我加了相同的CustomerDetail爲外鍵後。爲什麼運行遷移後仍然出現此錯誤,即使我在customer_id中添加了unique=True

Error: 
     Rendering model states... DONE 
     Applying newuser.0003_auto_20160823_0128...Traceback (most recent call last): 
      File "/home/krag91/Documents/djangodev/virtualenv /lib/python3.5/site-packages/django/db/backends/utils.py", line 64, in  execute 
    return self.cursor.execute(sql, params) 
      File "/home/krag91/Documents/djangodev/virtualenv /lib/python3.5/site-packages/django/db/backends/sqlite3/base.py", line 337, in execute 
    return Database.Cursor.execute(self, query, params) 
     sqlite3.IntegrityError: UNIQUE constraint failed:  newuser_customer.customer_id 
The above exception was the direct cause of the following exception: 

Traceback (most recent call last): 
    File "manage.py", line 22, in <module> 
    execute_from_command_line(sys.argv) 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/core/management/__init__.py", line 367, in execute_from_command_line utility.execute() 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/core/management/__init__.py", line 359, in execute 
    self.fetch_command(subcommand).run_from_argv(self.argv) 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/core/management/base.py", line 305, in run_from_argv 
    self.execute(*args, **cmd_options) 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/core/management/base.py", line 356, in execute 
    output = self.handle(*args, **options) 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/core/management/commands/migrate.py", line 202, in handle 
    targets, plan, fake=fake, fake_initial=fake_initial 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/db/migrations/executor.py", line 97, in migrate 
    state = self._migrate_all_forwards(plan, full_plan, fake=fake, fake_initial=fake_initial) 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/db/migrations/executor.py", line 132, in _migrate_all_forwards 
    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial) 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/db/migrations/executor.py", line 237, in apply_migration 
    state = migration.apply(state, schema_editor) 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/db/migrations/migration.py", line 129, in apply 
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state) 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/db/migrations/operations/fields.py", line 84, in database_forwards 
    field, 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/db/backends/sqlite3/schema.py", line 231, in add_field 
    self._remake_table(model, create_fields=[field]) 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/db/backends/sqlite3/schema.py", line 199, in _remake_table 
    self.quote_name(model._meta.db_table), 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/db/backends/base/schema.py", line 112, in execute 
    cursor.execute(sql, params) 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/db/backends/utils.py", line 79, in execute 
    return super(CursorDebugWrapper, self).execute(sql, params) 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/db/backends/utils.py", line 64, in execute 
    return self.cursor.execute(sql, params) 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/db/utils.py", line 94, in __exit__ 
    six.reraise(dj_exc_type, dj_exc_value, traceback) 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/utils/six.py", line 685, in reraise 
    raise value.with_traceback(tb) 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/db/backends/utils.py", line 64, in execute 
    return self.cursor.execute(sql, params) 
    File "/home/krag91/Documents/djangodev/virtualenv/lib/python3.5/site-packages/django/db/backends/sqlite3/base.py", line 337, in execute 
    return Database.Cursor.execute(self, query, params) 
django.db.utils.IntegrityError: UNIQUE constraint failed: newuser_customer.customer_id 

回答

0

看起來好像你是already having some objects as per old model definitionsBy default django creates a field named as id to every model in database。它可以通過modelName.id進行訪問。

在你的情況下,我猜想發生了什麼事情是你的數據庫中有一些對象,其中customer.id是主鍵。所以當你改變模型和應用遷移時,existing objects are checked and another unique field is tried to added as a primary key。此處的解決方法是在刪除customer_id字段後刪除所有現有對象,然後嘗試重新創建該字段並運行遷移。

HTH

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