Django 导入导出 - UNIQUE 约束失败
Django Import Export - UNIQUE constraint failed
我正在关注有关如何使用 django-import-export 的文档：
https://django-import-export.readthedocs.io/en/latest/getting_started.html#declaring-fields
我有一个 excel sheet 如下所示
我想在这个模型中存储数据：
class ExcelData(models.Model):
var1 = models.CharField(max_length=200)
var2 = models.CharField(max_length=200,unique=True)
var3 = models.CharField(max_length=200)
var4 = models.CharField(max_length=200)
这是我得到的结果：
@admin.register(ExcelData)
class ViewAdmin(ImportExportModelAdmin):
exclude = ('id',)
class ExcelDataResource(resources.ModelResource):
var1 = Field(attribute='var1', column_name='Name')
var2 = Field(attribute='var2', column_name='SAP_ID')
var3 = Field(attribute='var3', column_name='Abbreviation')
var4 = Field(attribute='var4', column_name='Max. Capa')
class Meta:
model = ExcelData
import_id_fields = ('var2',)
exclude = ('id',)
这是我得到的：
这是 CSV 文件：
http://www.sharecsv.com/s/9d1112392cd7f10378de7fc0811dd0c9/REAL_CSV_SIMPLE.csv
当我尝试像这样导入多行时：
我收到这个错误：
Line number: 2 - UNIQUE constraint failed: myapp_exceldata.var2
b, e, h, k
Traceback (most recent call last):
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
return self.cursor.execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\backends\sqlite3\base.py", line 396, in execute
return Database.Cursor.execute(self, query, params)
sqlite3.IntegrityError: UNIQUE constraint failed: myapp_exceldata.var2
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "D:\Users\...\env\lib\site-packages\import_export\resources.py", line 527, in import_row
self.save_instance(instance, using_transactions, dry_run)
File "D:\Users\...\env\lib\site-packages\import_export\resources.py", line 320, in save_instance
instance.save()
File "D:\Users\...\env\lib\site-packages\django\db\models\base.py", line 746, in save
force_update=force_update, update_fields=update_fields)
File "D:\Users\...\env\lib\site-packages\django\db\models\base.py", line 784, in save_base
force_update, using, update_fields,
File "D:\Users\...\env\lib\site-packages\django\db\models\base.py", line 887, in _save_table
results = self._do_insert(cls._base_manager, using, fields, returning_fields, raw)
File "D:\Users\...\env\lib\site-packages\django\db\models\base.py", line 926, in _do_insert
using=using, raw=raw,
File "D:\Users\...\env\lib\site-packages\django\db\models\manager.py", line 82, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "D:\Users\...\env\lib\site-packages\django\db\models\query.py", line 1204, in _insert
return query.get_compiler(using=using).execute_sql(returning_fields)
File "D:\Users\...\env\lib\site-packages\django\db\models\sql\compiler.py", line 1384, in execute_sql
cursor.execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 100, in execute
return super().execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 68, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 77, in _execute_with_wrappers
return executor(sql, params, many, context)
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
return self.cursor.execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\utils.py", line 90, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
return self.cursor.execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\backends\sqlite3\base.py", line 396, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.IntegrityError: UNIQUE constraint failed: myapp_exceldata.var2
Line number: 3 - UNIQUE constraint failed: myapp_exceldata.var2
c, f, i, l
Traceback (most recent call last):
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
return self.cursor.execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\backends\sqlite3\base.py", line 396, in execute
return Database.Cursor.execute(self, query, params)
sqlite3.IntegrityError: UNIQUE constraint failed: myapp_exceldata.var2
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "D:\Users\...\env\lib\site-packages\import_export\resources.py", line 527, in import_row
self.save_instance(instance, using_transactions, dry_run)
File "D:\Users\...\env\lib\site-packages\import_export\resources.py", line 320, in save_instance
instance.save()
File "D:\Users\...\env\lib\site-packages\django\db\models\base.py", line 746, in save
force_update=force_update, update_fields=update_fields)
File "D:\Users\...\env\lib\site-packages\django\db\models\base.py", line 784, in save_base
force_update, using, update_fields,
File "D:\Users\...\env\lib\site-packages\django\db\models\base.py", line 887, in _save_table
results = self._do_insert(cls._base_manager, using, fields, returning_fields, raw)
File "D:\Users\...\env\lib\site-packages\django\db\models\base.py", line 926, in _do_insert
using=using, raw=raw,
File "D:\Users\...\env\lib\site-packages\django\db\models\manager.py", line 82, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "D:\Users\...\env\lib\site-packages\django\db\models\query.py", line 1204, in _insert
return query.get_compiler(using=using).execute_sql(returning_fields)
File "D:\Users\...\env\lib\site-packages\django\db\models\sql\compiler.py", line 1384, in execute_sql
cursor.execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 100, in execute
return super().execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 68, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 77, in _execute_with_wrappers
return executor(sql, params, many, context)
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
return self.cursor.execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\utils.py", line 90, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
return self.cursor.execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\backends\sqlite3\base.py", line 396, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.IntegrityError: UNIQUE constraint failed: myapp_exceldata.var2
这是 CSV 文件：
http://www.sharecsv.com/s/3f09eb14f7916933604481fd999d03db/REAL_CSV_FULL.csv
感谢您的任何建议
导入的工作方式如下：
- 您需要一个唯一标识符，以便在导入时，导入导出模块"knows"是否需要创建新行或修改现有行。
- 如果该唯一标识符不是模型的
id 字段（在您的情况下是自动递增的行号），那么它必须是其他一些唯一字段。 None 的字段 var1 ... var4 在您的模型中被声明为唯一的，因此由于您当前已经定义了您的模型，因此无法导入。
- 如果字段的 组合 在一起是唯一的，您可以使用多个 "id fields"，但在您的模型中也不是这种情况。
- 导入模块实际上对您的数据库执行
get_or_create() 调用，使用 unique_id_fields 作为获取参数。这不应该 return 超过 1 行，如果是 return 多行，导入会崩溃。
给你一个想法，假设 SAP_ID 是一个唯一的标识符（我怀疑 Max. Capacity 是，名字并不表明它会是），这应该是你的模型：
class ExcelData(models.Model):
var1 = models.CharField(max_length=200)
var2 = models.CharField(max_length=200, unique=True)
var3 = models.CharField(max_length=200)
var4 = models.CharField(max_length=200)
请注意，您的模型也有隐式字段 id，导入导出知道该字段，您必须决定如何处理它，因为它不在您的导入数据中。这就是您收到您提到的错误的原因，因为它是您模型中尚未分配给任何内容的字段。最好是排除它，因为它在这里不相关（如果该行尚不存在，Django 将自动增加一个新的 id，就像您使用 ExcelData.objects.create() 创建模型时一样）：
class ExcelDataResource(resources.ModelResource):
var1 = Field(attribute='var1', column_name='Name')
var2 = Field(attribute='var2', column_name='SAP_ID')
var3 = Field(attribute='var3', column_name='Abbreviation')
var4 = Field(attribute='var4', column_name='Max. Capa')
class Meta:
model = ExcelData
import_id_fields = ('var2',)
exclude = ('id',)
使用此代码和以下 csv 文件，它可以工作，我已经对其进行了测试：
Name,SAP_ID,Abbreviation,Max. Capa
a,d,g,j
b,e,h,k
c,f,i,l
第二次尝试导入时，或者如果数据库中已有一些数据 var2 的值为 d、e 或 f，您将收到 UNIQUE constraint failed 错误 exceldata.var2.
注意：如果 Max. Capa 确实是您唯一的 id 字段，那么您不应将其分配给 var4，而应分配给 id。这也行得通，尽管正如我上面提到的，我怀疑这是你想要的行为。
UPDATE/Note 2: django-import-export中有一个bug会造成UNIQUE约束当您尝试 更新现有数据 时出现异常：如果您的 unique_id_field 与您导入的数据中的 column_name 名称不同（例如 var2 对于 SAP_ID) 并且您尝试 重新导入数据 其中包含具有相同 ID 的已经存在的行（例如因为您想要 change 其他值）。它应该 更新 该行，但目前它抛出异常。这并不能解释 var4 上的异常（那是因为您将 var4 也设置为唯一的，并且如果您导入具有重复 var4 (Max. Capa) 的不同行值，那么你也会得到一个例外）。
我正在关注有关如何使用 django-import-export 的文档：
https://django-import-export.readthedocs.io/en/latest/getting_started.html#declaring-fields
我有一个 excel sheet 如下所示
我想在这个模型中存储数据：
class ExcelData(models.Model):
var1 = models.CharField(max_length=200)
var2 = models.CharField(max_length=200,unique=True)
var3 = models.CharField(max_length=200)
var4 = models.CharField(max_length=200)
这是我得到的结果：
@admin.register(ExcelData)
class ViewAdmin(ImportExportModelAdmin):
exclude = ('id',)
class ExcelDataResource(resources.ModelResource):
var1 = Field(attribute='var1', column_name='Name')
var2 = Field(attribute='var2', column_name='SAP_ID')
var3 = Field(attribute='var3', column_name='Abbreviation')
var4 = Field(attribute='var4', column_name='Max. Capa')
class Meta:
model = ExcelData
import_id_fields = ('var2',)
exclude = ('id',)
这是我得到的：
这是 CSV 文件：
http://www.sharecsv.com/s/9d1112392cd7f10378de7fc0811dd0c9/REAL_CSV_SIMPLE.csv
当我尝试像这样导入多行时：
我收到这个错误：
Line number: 2 - UNIQUE constraint failed: myapp_exceldata.var2
b, e, h, k
Traceback (most recent call last):
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
return self.cursor.execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\backends\sqlite3\base.py", line 396, in execute
return Database.Cursor.execute(self, query, params)
sqlite3.IntegrityError: UNIQUE constraint failed: myapp_exceldata.var2
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "D:\Users\...\env\lib\site-packages\import_export\resources.py", line 527, in import_row
self.save_instance(instance, using_transactions, dry_run)
File "D:\Users\...\env\lib\site-packages\import_export\resources.py", line 320, in save_instance
instance.save()
File "D:\Users\...\env\lib\site-packages\django\db\models\base.py", line 746, in save
force_update=force_update, update_fields=update_fields)
File "D:\Users\...\env\lib\site-packages\django\db\models\base.py", line 784, in save_base
force_update, using, update_fields,
File "D:\Users\...\env\lib\site-packages\django\db\models\base.py", line 887, in _save_table
results = self._do_insert(cls._base_manager, using, fields, returning_fields, raw)
File "D:\Users\...\env\lib\site-packages\django\db\models\base.py", line 926, in _do_insert
using=using, raw=raw,
File "D:\Users\...\env\lib\site-packages\django\db\models\manager.py", line 82, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "D:\Users\...\env\lib\site-packages\django\db\models\query.py", line 1204, in _insert
return query.get_compiler(using=using).execute_sql(returning_fields)
File "D:\Users\...\env\lib\site-packages\django\db\models\sql\compiler.py", line 1384, in execute_sql
cursor.execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 100, in execute
return super().execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 68, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 77, in _execute_with_wrappers
return executor(sql, params, many, context)
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
return self.cursor.execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\utils.py", line 90, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
return self.cursor.execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\backends\sqlite3\base.py", line 396, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.IntegrityError: UNIQUE constraint failed: myapp_exceldata.var2
Line number: 3 - UNIQUE constraint failed: myapp_exceldata.var2
c, f, i, l
Traceback (most recent call last):
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
return self.cursor.execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\backends\sqlite3\base.py", line 396, in execute
return Database.Cursor.execute(self, query, params)
sqlite3.IntegrityError: UNIQUE constraint failed: myapp_exceldata.var2
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "D:\Users\...\env\lib\site-packages\import_export\resources.py", line 527, in import_row
self.save_instance(instance, using_transactions, dry_run)
File "D:\Users\...\env\lib\site-packages\import_export\resources.py", line 320, in save_instance
instance.save()
File "D:\Users\...\env\lib\site-packages\django\db\models\base.py", line 746, in save
force_update=force_update, update_fields=update_fields)
File "D:\Users\...\env\lib\site-packages\django\db\models\base.py", line 784, in save_base
force_update, using, update_fields,
File "D:\Users\...\env\lib\site-packages\django\db\models\base.py", line 887, in _save_table
results = self._do_insert(cls._base_manager, using, fields, returning_fields, raw)
File "D:\Users\...\env\lib\site-packages\django\db\models\base.py", line 926, in _do_insert
using=using, raw=raw,
File "D:\Users\...\env\lib\site-packages\django\db\models\manager.py", line 82, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "D:\Users\...\env\lib\site-packages\django\db\models\query.py", line 1204, in _insert
return query.get_compiler(using=using).execute_sql(returning_fields)
File "D:\Users\...\env\lib\site-packages\django\db\models\sql\compiler.py", line 1384, in execute_sql
cursor.execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 100, in execute
return super().execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 68, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 77, in _execute_with_wrappers
return executor(sql, params, many, context)
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
return self.cursor.execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\utils.py", line 90, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "D:\Users\...\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
return self.cursor.execute(sql, params)
File "D:\Users\...\env\lib\site-packages\django\db\backends\sqlite3\base.py", line 396, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.IntegrityError: UNIQUE constraint failed: myapp_exceldata.var2
这是 CSV 文件：
http://www.sharecsv.com/s/3f09eb14f7916933604481fd999d03db/REAL_CSV_FULL.csv
感谢您的任何建议
导入的工作方式如下：
- 您需要一个唯一标识符，以便在导入时，导入导出模块"knows"是否需要创建新行或修改现有行。
- 如果该唯一标识符不是模型的
id字段（在您的情况下是自动递增的行号），那么它必须是其他一些唯一字段。 None 的字段var1...var4在您的模型中被声明为唯一的，因此由于您当前已经定义了您的模型，因此无法导入。 - 如果字段的 组合 在一起是唯一的，您可以使用多个 "id fields"，但在您的模型中也不是这种情况。
- 导入模块实际上对您的数据库执行
get_or_create()调用，使用unique_id_fields作为获取参数。这不应该 return 超过 1 行，如果是 return 多行，导入会崩溃。
给你一个想法，假设 SAP_ID 是一个唯一的标识符（我怀疑 Max. Capacity 是，名字并不表明它会是），这应该是你的模型：
class ExcelData(models.Model):
var1 = models.CharField(max_length=200)
var2 = models.CharField(max_length=200, unique=True)
var3 = models.CharField(max_length=200)
var4 = models.CharField(max_length=200)
请注意，您的模型也有隐式字段 id，导入导出知道该字段，您必须决定如何处理它，因为它不在您的导入数据中。这就是您收到您提到的错误的原因，因为它是您模型中尚未分配给任何内容的字段。最好是排除它，因为它在这里不相关（如果该行尚不存在，Django 将自动增加一个新的 id，就像您使用 ExcelData.objects.create() 创建模型时一样）：
class ExcelDataResource(resources.ModelResource):
var1 = Field(attribute='var1', column_name='Name')
var2 = Field(attribute='var2', column_name='SAP_ID')
var3 = Field(attribute='var3', column_name='Abbreviation')
var4 = Field(attribute='var4', column_name='Max. Capa')
class Meta:
model = ExcelData
import_id_fields = ('var2',)
exclude = ('id',)
使用此代码和以下 csv 文件，它可以工作，我已经对其进行了测试：
Name,SAP_ID,Abbreviation,Max. Capa
a,d,g,j
b,e,h,k
c,f,i,l
第二次尝试导入时，或者如果数据库中已有一些数据 var2 的值为 d、e 或 f，您将收到 UNIQUE constraint failed 错误 exceldata.var2.
注意：如果 Max. Capa 确实是您唯一的 id 字段，那么您不应将其分配给 var4，而应分配给 id。这也行得通，尽管正如我上面提到的，我怀疑这是你想要的行为。
UPDATE/Note 2: django-import-export中有一个bug会造成UNIQUE约束当您尝试 更新现有数据 时出现异常：如果您的 unique_id_field 与您导入的数据中的 column_name 名称不同（例如 var2 对于 SAP_ID) 并且您尝试 重新导入数据 其中包含具有相同 ID 的已经存在的行（例如因为您想要 change 其他值）。它应该 更新 该行，但目前它抛出异常。这并不能解释 var4 上的异常（那是因为您将 var4 也设置为唯一的，并且如果您导入具有重复 var4 (Max. Capa) 的不同行值，那么你也会得到一个例外）。