实体框架未保存生产环境中的更改
本文关键字:生产环境 框架 保存 实体 | 更新日期: 2023-09-27 18:35:39
我正在编写一个与EF和MySql一起使用的桌面应用程序。EF 创建的每种类型都有一个到本地类型的映射。当使用Visual Studio提供的单元测试框架测试包装器方法时,所有测试都会运行 - 我看到进出数据库的信息。但是,当我从为集成测试添加的临时控制台程序运行相同的代码时,EF 会引发以下异常:
System.NullReferenceException: Object reference not set to an instance of an object.
at MySql.Data.MySqlClient.MySqlClientFactory.get_MySqlDbProviderServicesInstance()
at MySql.Data.MySqlClient.MySqlClientFactory.System.IServiceProvider.GetService(Type serviceType)
at System.Data.Common.DbProviderServices.GetProviderServices(DbProviderFactory factory)
at System.Data.Metadata.Edm.StoreItemCollection.Loader.InitializeProviderManifest(Action`3 addError)
at System.Data.Metadata.Edm.StoreItemCollection.Loader.OnProviderManifestTokenNotification(String token, Action`3 addError)
at System.Data.EntityModel.SchemaObjectModel.Schema.HandleProviderManifestTokenAttribute(XmlReader reader)
at System.Data.EntityModel.SchemaObjectModel.Schema.HandleAttribute(XmlReader reader)
at System.Data.EntityModel.SchemaObjectModel.SchemaElement.ParseAttribute(XmlReader reader)
at System.Data.EntityModel.SchemaObjectModel.SchemaElement.Parse(XmlReader reader)
at System.Data.EntityModel.SchemaObjectModel.Schema.HandleTopLevelSchemaElement(XmlReader reader)
at System.Data.EntityModel.SchemaObjectModel.Schema.InternalParse(XmlReader sourceReader, String sourceLocation)
at System.Data.EntityModel.SchemaObjectModel.Schema.Parse(XmlReader sourceReader, String sourceLocation)
at System.Data.EntityModel.SchemaObjectModel.SchemaManager.ParseAndValidate(IEnumerable`1 xmlReaders, IEnumerable`1 sourceFilePaths, SchemaDataModelOption dataModel, AttributeValueNotification providerNotification, AttributeValueNotification providerManifestTokenNotification, ProviderManifestNeed
ed providerManifestNeeded, IList`1& schemaCollection)
at System.Data.Metadata.Edm.StoreItemCollection.Loader.LoadItems(IEnumerable`1 xmlReaders, IEnumerable`1 sourceFilePaths)
at System.Data.Metadata.Edm.StoreItemCollection.Init(IEnumerable`1 xmlReaders, IEnumerable`1 filePaths, Boolean throwOnError, DbProviderManifest& providerManifest, DbProviderFactory& providerFactory, String& providerManifestToken, Memoizer`2& cachedCTypeFunction)
at System.Data.Metadata.Edm.StoreItemCollection..ctor(IEnumerable`1 xmlReaders, IEnumerable`1 filePaths)
at System.Data.Metadata.Edm.MetadataCache.StoreMetadataEntry.LoadStoreCollection(EdmItemCollection edmItemCollection, MetadataArtifactLoader loader)
at System.Data.Metadata.Edm.MetadataCache.StoreItemCollectionLoader.LoadItemCollection(StoreMetadataEntry entry)
at System.Data.Metadata.Edm.MetadataCache.LoadItemCollection[T](IItemCollectionLoader`1 itemCollectionLoader, T entry)
at System.Data.Metadata.Edm.MetadataCache.GetOrCreateStoreAndMappingItemCollections(String cacheKey, MetadataArtifactLoader loader, EdmItemCollection edmItemCollection, Object& entryToken)
at System.Data.EntityClient.EntityConnection.LoadStoreItemCollections(MetadataWorkspace workspace, DbConnection storeConnection, DbProviderFactory factory, DbConnectionOptions connectionOptions, EdmItemCollection edmItemCollection, MetadataArtifactLoader artifactLoader)
at System.Data.EntityClient.EntityConnection.GetMetadataWorkspace(Boolean initializeAllCollections)
at System.Data.EntityClient.EntityConnection.InitializeMetadata(DbConnection newConnection, DbConnection originalConnection, Boolean closeOriginalConnectionOnFailure)
at System.Data.EntityClient.EntityConnection.Open()
at System.Data.Objects.ObjectContext.EnsureConnection()
at System.Data.Objects.ObjectContext.SaveChanges(SaveOptions options)
at System.Data.Objects.ObjectContext.SaveChanges()
at DataAccess.PhoneTypeAccess.AddNewPhoneType(PhoneType newPhoneType) in C:'Users'Mordechai'Desktop'Progaming'GitHub'VirtualGabbai'VirtGabbai'DataAccess'PhoneTypeAccess.cs:line 66
at TempUI.Program.Main(String[] args) in C:'Users'Mordechai'Desktop'Progaming'GitHub'VirtualGabbai'VirtGabbai'TempUI'Program.cs:line 17
这是我在程序中运行的代码.cs
static void Main(string[] args)
{
try
{
PhoneTypeAccess.AddNewPhoneType(new PhoneType(1, "phone"));
var blah = PhoneTypeAccess.GetPhoneTypeById(1);
Console.WriteLine(blah.ToString());
//Cache.CacheData.t_phone_types.AddObject(t_phone_types.Createt_phone_types(1, "some Type"));
//var thingOne = t_people.Createt_people(1);
//Cache.CacheData.t_people.AddObject(thingOne);
//Cache.CacheData.SaveChanges();
//PhoneNumberAccess.AddNewPhoneNumber(new PhoneNumber(1, "some number", new PhoneType(1, "some type")));
//var test = PhoneNumberAccess.GetPhoneNumberById(1);
//Console.WriteLine(test.ToString
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
测试包含以下代码
[TestMethod()]
public void AddNewPhoneTypeTest()
{
PhoneType newPhoneType = new PhoneType(21, "phonetype:21");
PhoneTypeAccess.AddNewPhoneType(newPhoneType);
PhoneType actual = PhoneTypeAccess.GetPhoneTypeById(21);
Assert.IsTrue(newPhoneType.Equals(actual));
}
调用的代码如下
public static void AddNewPhoneType(PhoneType newPhoneType)
{
t_phone_types phoneTypeToAdd = PhoneTypeAccess.ConvertSingleLocalPhoneTypeToDbType(newPhoneType);
Cache.CacheData.t_phone_types.AddObject(phoneTypeToAdd);
Cache.CacheData.SaveChanges();
}
当我在第 Cache.CacheData.SaveChanges()
行进行调试时,我得到以下代码
/// <summary>
/// Allows access to the cached data - but only a single (and constant) instance of it
/// -[the code can create another one but it will be a completly different set of data]-
/// </summary>
public static class Cache
{
// Data members
private static zera_leviEntities m_dsDataSet = new zera_leviEntities();
/// <summary>
/// Allows outside access to the main data set
/// - without letting the user access it any other way
/// </summary>
public static zera_leviEntities CacheData
{
get
{
return m_dsDataSet;
}
}
}
我唯一能看到的是,在实体集中确实没有对象。 但没有说明为什么我看遍了四周,没有找到任何有用的东西。我被困住了,直到我开始运行,所以我希望有人可以帮助我谢谢
编辑:在转换方法中添加
private static t_phone_types ConvertSingleLocalPhoneTypeToDbType(PhoneType localTypePhoneType)
{
return t_phone_types.Createt_phone_types(localTypePhoneType._Id, localTypePhoneType.PhoneTypeName);
}
t_phone_types。Createt_phone_types() 方法是 EF 的一部分
编辑:我现在通过将整个解决方案中的引用更改为MySql适配器的更新版本来设法打破测试现在,测试也抛出相同的异常。此外,在构建时出现以下错误:
Error 4: Could not load file or assembly 'MySql.Data, Version=6.7.4.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) C:'Users'Mordechai'Desktop'Progaming'GitHub'VirtualGabbai'VirtGabbai'Data'EntityCache.edmx
但是,它仍然会运行(只是它抛出了异常)
嗯....,经过多次试验和错误,我设法找出了问题。MySQl 适配器分为两部分。一个用于所有连接,另一个用于专门与 EF 连接。现在我添加了第二个 dll,一切运行正常。