我在单元测试中遇到了数据库问题。我认为这与我使用TestCase和setUpData的方式有关。
当我尝试使用某些值设置测试数据时，测试会抛出以下错误：
django.db.utils.IntegrityError: duplicate key value violates unique constraint
...
psycopg2.IntegrityError: duplicate key value violates unique constraint "InventoryLogs_productgroup_product_name_48ec6f8d_uniq"
DETAIL: Key (product_name)=(Almonds) already exists.
我更改了所有主键，似乎运行正常。它似乎不影响任何测试。
然而，我担心我做错了什么。当它第一次发生时，我在我的应用程序上反转了大约一个小时的工作量（没有那么多的菜鸟代码），这纠正了问题。
然后，当我重新写入更改时，同样的问题又出现了。 TestCase粘贴在下面。在我添加sortrecord项目后，问题似乎发生了，但与上面的项目相对应。
我不想在我的测试中继续检查和更改主键和网址，所以如果有人发现我使用它的方式有问题，请帮助我。谢谢！
测试用例
class DetailsPageTest(TestCase):
@classmethod
def setUpTestData(cls):
cls.product1 = ProductGroup.objects.create(
product_name="Almonds"
)
cls.variety1 = Variety.objects.create(
product_group = cls.product1,
variety_name = "non pareil",
husked = False,
finished = False,
)
cls.supplier1 = Supplier.objects.create(
company_name = "Acme",
company_location = "Acme Acres",
contact_info = "Call me!"
)
cls.shipment1 = Purchase.objects.create(
tag=9,
shipment_id=9999,
supplier_id = cls.supplier1,
purchase_date='2015-01-09',
purchase_price=9.99,
product_name=cls.variety1,
pieces=99,
kgs=999,
crackout_estimate=99.9
)
cls.shipment2 = Purchase.objects.create(
tag=8,
shipment_id=8888,
supplier_id=cls.supplier1,
purchase_date='2015-01-08',
purchase_price=8.88,
product_name=cls.variety1,
pieces=88,
kgs=888,
crackout_estimate=88.8
)
cls.shipment3 = Purchase.objects.create(
tag=7,
shipment_id=7777,
supplier_id=cls.supplier1,
purchase_date='2014-01-07',
purchase_price=7.77,
product_name=cls.variety1,
pieces=77,
kgs=777,
crackout_estimate=77.7
)
cls.sortrecord1 = SortingRecords.objects.create(
tag=cls.shipment1,
date="2015-02-05",
bags_sorted=20,
turnout=199,
)
cls.sortrecord2 = SortingRecords.objects.create(
tag=cls.shipment1,
date="2015-02-07",
bags_sorted=40,
turnout=399,
)
cls.sortrecord3 = SortingRecords.objects.create(
tag=cls.shipment1,
date='2015-02-09',
bags_sorted=30,
turnout=299,
)
模型
from datetime import datetime
from django.db import models
from django.db.models import Q
class ProductGroup(models.Model):
product_name = models.CharField(max_length=140, primary_key=True)
def __str__(self):
return self.product_name
class Meta:
verbose_name = "Product"
class Supplier(models.Model):
company_name = models.CharField(max_length=45)
company_location = models.CharField(max_length=45)
contact_info = models.CharField(max_length=256)
class Meta:
ordering = ["company_name"]
def __str__(self):
return self.company_name
class Variety(models.Model):
product_group = models.ForeignKey(ProductGroup)
variety_name = models.CharField(max_length=140)
husked = models.BooleanField()
finished = models.BooleanField()
description = models.CharField(max_length=500, blank=True)
class Meta:
ordering = ["product_group_id"]
verbose_name_plural = "Varieties"
def __str__(self):
return self.variety_name
class PurchaseYears(models.Manager):
def purchase_years_list(self):
unique_years = Purchase.objects.dates('purchase_date', 'year')
results_list = []
for p in unique_years:
results_list.append(p.year)
return results_list
class Purchase(models.Model):
tag = models.IntegerField(primary_key=True)
product_name = models.ForeignKey(Variety, related_name='purchases')
shipment_id = models.CharField(max_length=24)
supplier_id = models.ForeignKey(Supplier)
purchase_date = models.DateField()
estimated_delivery = models.DateField(null=True, blank=True)
purchase_price = models.DecimalField(max_digits=6, decimal_places=3)
pieces = models.IntegerField()
kgs = models.IntegerField()
crackout_estimate = models.DecimalField(max_digits=6,decimal_places=3, null=True)
crackout_actual = models.DecimalField(max_digits=6,decimal_places=3, null=True)
objects = models.Manager()
purchase_years = PurchaseYears()
# Keep manager as "objects" in case admin, etc. needs it. Filter can be called like so:
# Purchase.objects.purchase_years_list()
# Managers in docs: https://docs.djangoproject.com/en/1.8/intro/tutorial01/
class Meta:
ordering = ["purchase_date"]
def __str__(self):
return self.shipment_id
def _weight_conversion(self):
return round(self.kgs * 2.20462)
lbs = property(_weight_conversion)
class SortingModelsBagsCalulator(models.Manager):
def total_sorted(self, record_date, current_set):
sorted = [SortingRecords['bags_sorted'] for SortingRecords in current_set if
SortingRecords['date'] <= record_date]
return sum(sorted)
class SortingRecords(models.Model):
tag = models.ForeignKey(Purchase, related_name='sorting_record')
date = models.DateField()
bags_sorted = models.IntegerField()
turnout = models.IntegerField()
objects = models.Manager()
def __str__(self):
return "%s [%s]" % (self.date, self.tag.tag)
class Meta:
ordering = ["date"]
verbose_name_plural = "Sorting Records"
def _calculate_kgs_sorted(self):
kg_per_bag = self.tag.kgs / self.tag.pieces
kgs_sorted = kg_per_bag * self.bags_sorted
return (round(kgs_sorted, 2))
kgs_sorted = property(_calculate_kgs_sorted)
def _byproduct(self):
waste = self.kgs_sorted - self.turnout
return (round(waste, 2))
byproduct = property(_byproduct)
def _bags_remaining(self):
current_set = SortingRecords.objects.values().filter(~Q(id=self.id), tag=self.tag)
sorted = [SortingRecords['bags_sorted'] for SortingRecords in current_set if
SortingRecords['date'] <= self.date]
remaining = self.tag.pieces - sum(sorted) - self.bags_sorted
return remaining
bags_remaining = property(_bags_remaining)
修改
它也会因整数而失败。
django.db.utils.IntegrityError: duplicate key value violates unique constraint "InventoryLogs_purchase_pkey"
DETAIL: Key (tag)=(9) already exists.
UDPATE
所以我早些时候应该提到这一点，但我完全忘记了。我有两个使用相同数据的单元测试文件。只是为了踢，我在setUpTestData()的两个实例中将主键与不同的值匹配，果然，我得到了同样的错误。
在我向其中一个添加更多数据之前，这两个设置并排运行良好。现在，他们似乎需要不同的价值观。我想你只能使用重复数据这么长时间。
答案 0 :(得分：3)
几个月来，我一直不时遇到这个问题。我相信我已经找到了根本原因和一些解决方案。
摘要
无论出于何种原因，似乎Django测试用例的基类都没有删除由我们创建的数据库记录（在运行using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Windows.Forms;
[DesignerCategory("Code")]
class DateTimePickerYearMonth : DateTimePicker
{
[DllImport("user32.dll")]
static extern IntPtr SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);
private const int DTM_FIRST = 0x1000;
private const int DTM_GETMONTHCAL = DTM_FIRST + 8;
private const int DTM_SETMCSTYLE = DTM_FIRST + 11;
private const int DTM_GETMCSTYLE = DTM_FIRST + 12;
private const int MCM_FIRST = 0x1000;
private const int MCM_GETCURRENTVIEW = MCM_FIRST + 22;
private const int MCM_SETCURRENTVIEW = MCM_FIRST + 32;
private bool m_ShowToday = false;
public enum MonCalView : int
{
MCMV_MONTH = 0,
MCMV_YEAR = 1,
MCMV_DECADE = 2,
MCMV_CENTURY = 3
}
public enum MonCalStyles : int
{
MCS_DAYSTATE = 0x0001,
MCS_MULTISELECT = 0x0002,
MCS_WEEKNUMBERS = 0x0004,
MCS_NOTODAYCIRCLE = 0x0008,
MCS_NOTODAY = 0x0010,
MCS_NOTRAILINGDATES = 0x0040,
MCS_SHORTDAYSOFWEEK = 0x0080,
MCS_NOSELCHANGEONNAV = 0x0100
}
public DateTimePickerYearMonth() {
this.CustomFormat = "MM-yyyy";
this.Format = DateTimePickerFormat.Custom;
this.Value = DateTime.Now;
}
[
Browsable(true), EditorBrowsable(EditorBrowsableState.Always), DefaultValue(false),
Category("Appearance"),
Description("Shows or hides \"Today\" date at the bottom of the Calendar Control")
]
public bool ShowToday {
get => m_ShowToday;
set {
if (value != m_ShowToday) {
m_ShowToday = value;
ShowMonCalToday(m_ShowToday);
}
}
}
protected override void OnHandleCreated(EventArgs e)
{
base.OnHandleCreated(e);
ShowMonCalToday(m_ShowToday);
}
protected override void OnDropDown(EventArgs e)
{
var hWnd = SendMessage(this.Handle, DTM_GETMONTHCAL, 0, 0);
if (hWnd != IntPtr.Zero) {
SendMessage(hWnd, MCM_SETCURRENTVIEW, 0, (int)MonCalView.MCMV_YEAR);
}
base.OnDropDown(e);
}
private void ShowMonCalToday(bool show)
{
int styles = SendMessage(this.Handle, DTM_GETMCSTYLE, 0, 0).ToInt32();
styles = show ? styles &~(int)MonCalStyles.MCS_NOTODAY : styles | (int)MonCalStyles.MCS_NOTODAY;
SendMessage(this.Handle, DTM_SETMCSTYLE, 0, styles);
}
}
之前将其命名为TestCase1）。在TestCase2中，当尝试使用与TestCase2相同的ID在数据库中创建记录时，数据库会引发TestCase1异常，因为这些ID已存在于数据库中。甚至说出神奇的单词“ please”也不会帮助解决数据库重复的键错误。
好消息是，有多种方法可以解决此问题！这是一对...
解决方案1
请确保您是否覆盖要调用的DuplicateKey类方法tearDownClass。如果您覆盖super().tearDownClass()而未调用其超级，则它将永远不会调用tearDownClass()或TransactionTestCase._post_teardown()。引用TransactionTestCase._post_teardown（）`中的文档字符串：
TransactionTestCase._fixture_teardown()如果未通过 def _post_teardown(self):
"""
Perform post-test things:
* Flush the contents of the database to leave a clean slate. If the
class has an 'available_apps' attribute, don't fire post_migrate.
* Force-close the connection so the next test gets a clean cursor.
"""
调用TestCase.tearDownClass()，则在测试用例之间不会重置数据库，您将得到可怕的重复密钥异常。
解决方案2
覆盖super()并设置类变量TransactionTestCase，如下所示：
serialized_rollback = True引用来源：
class MyTestCase(TransactionTestCase):
fixtures = ['test-data.json']
serialized_rollback = True
def test_name_goes_here(self):
pass
将class TransactionTestCase(SimpleTestCase):
...
# If transactions aren't available, Django will serialize the database
# contents into a fixture during setup and flush and reload them
# during teardown (as flush does not restore data from migrations).
# This can be slow; this flag allows enabling on a per-case basis.
serialized_rollback = False
设置为serialized_rollback时，Django测试运行器将回滚测试用例之间插入数据库的所有事务。还有batta bing，batta bang ...不再有重复的键错误！
结论
可能有更多的方法可以为OP的问题实施解决方案，但是这两种方法应该可以很好地工作。为了清楚起见，以及更深入地了解底层Django测试用例基类，绝对希望其他人添加更多解决方案。 ew，说最后一行真快三遍，您可以赢一匹小马！
答案 1 :(得分：1)
在没有任何重复数据的情况下，我继续遇到此错误，但是我能够通过初始化对象并调用result方法来解决此问题，而不是通过save()创建对象
换句话说，我做到了：
Model.objects.create()代替此：
@classmethod
def setUpTestData(cls):
cls.person = Person(first_name="Jane", last_name="Doe")
cls.person.save()
答案 2 :(得分：0)
您提供的日志指出DETAIL: Key (product_name)=(Almonds) already exists。你在数据库中验证了吗？
为防止将来出现此类错误，您应该在test_
答案 3 :(得分：0)
我发现了这个问题，如问题的底部所述。
据我所知，数据库不喜欢我在两个不同测试的setUpTestData()方法中使用重复数据。在第二次测试中更改主键值可以解决问题。
答案 4 :(得分：0)
我认为这里的问题是你的TestCase中有一个tearDownClass方法而没有调用super方法。 这样，django TestCase就丢失了setUpTestData背后的事务功能，因此在TestCase完成后它不会清理你的测试数据库。
在这里查看django文档中的警告： https://docs.djangoproject.com/en/1.10/topics/testing/tools/#django.test.SimpleTestCase.allow_database_queries
答案 5 :(得分：0)
我遇到了类似的问题，这是由显式地向测试用例提供主键值引起的。
如 the Django documentation 中所述，手动为自动递增字段分配值不会更新字段的序列，这可能会在以后导致冲突。
我已经通过手动更改顺序解决了这个问题：
from django.db import connection
class MyTestCase(TestCase):
@classmethod
def setUpTestData(cls):
Model.objects.create(id=1)
with connection.cursor() as c:
c.execute(
"""
ALTER SEQUENCE "app_model_id_seq" RESTART WITH 2;
"""
)