就我而言,我无法让我的C# WinApp使用MySql数据库,使用MySql连接器6.6.5.0 (MySql.Data参考资料)和MySql Entity 6.5.4.0 (MySql.Data.Entity参考资料)来处理Entity Framework5.0。在Visual Studio2012上使用.Net框架4.5。在撰写本文时,上面的版本都是最新的稳定版本。
这是我在app.config上的资料
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</configSections>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
</startup>
<system.data>
<DbProviderFactories>
<add name="MySQL Data Provider"
invariant="MySql.Data.MySqlClient"
description=".Net Framework Data Provider for MySQL"
type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data" />
</DbProviderFactories>
</system.data>
<connectionStrings>
<add name="MyConnectionName"
connectionString="Server=mysql13.myserver.com.br;Database=mydb;User Id=username;Pwd=pa$$w0rd;"
providerName="MySql.Data.MySqlClient" />
</connectionStrings>
<entityFramework>
<defaultConnectionFactory type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data">
</defaultConnectionFactory>
</entityFramework>
<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
<dependentAssembly>
<assemblyIdentity name="MySql.Data" publicKeyToken="c5687fc88969c44d" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-6.6.5.0" newVersion="6.6.5.0" />
</dependentAssembly>
</assemblyBinding>
</runtime>
</configuration>在代码中
用户类
public class User
{
public int Id { get; set; }
public string Name { get; set; }
public virtual List<Permission> Permissions { get; set; }
public User()
{
Permissions = new List<Permission>();
}
}
public class Permission
{
public int Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
}
public class UserContext : DbContext
{
public DbSet<User> Users { get; set; }
public DbSet<Permission> Permissions { get; set; }
}创建新记录
using (var db = new UserContext())
{
Permission permission1 = new Permission() { Name = "Permission 1", Description = "The desc 1" };
Permission permission2 = new Permission() { Name = "2nd Perm", Description = "Desc2" };
User user = new User() { Name = "Joao" };
user.Permissions.Add(permission1);
user.Permissions.Add(permission2);
db.Users.Add(user);
db.SaveChanges();
}我在db.Users.Add(user);行得到了一个异常
System.InvalidOperationException was unhandled
HResult=-2146233079
Message=Failed to set Database.DefaultConnectionFactory to an instance of the 'MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data' type as specified in the application configuration. See inner exception for details.
Source=EntityFramework
StackTrace:
at System.Data.Entity.Internal.AppConfig.<.ctor>b__1()
at System.Lazy`1.CreateValue()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Lazy`1.get_Value()
at System.Data.Entity.Internal.AppConfig.get_DefaultConnectionFactory()
[removing the rest of the stack]
InnerException: System.InvalidCastException
HResult=-2147467262
Message=Unable to cast object of type 'MySql.Data.MySqlClient.MySqlClientFactory' to type 'System.Data.Entity.Infrastructure.IDbConnectionFactory'.
Source=EntityFramework
StackTrace:
at System.Data.Entity.Internal.AppConfig.<.ctor>b__1()
InnerException: 我已经尝试了几种方法,包括在DbProviderFactories部分添加Culture=neutral, PublicKeyToken=c5687fc88969c44d,但都没有用。
我使用NuGet包管理器添加了实体框架、MySql数据连接器和MySql.Data.Entity。
我见过许多其他有类似问题的帖子,但找不到明确的解决方案,特别是版本组合EF 5+ MySql连接器6.6.5.0。
有没有人做到这一点?你能同时发布app.config和代码以使其工作吗?
发布于 2013-05-08 13:11:40
听起来好像有一些奇怪的程序集解析问题。尝试删除配置文件中的assemblyBinding元素,然后运行NuGet的Add-BindingRedirect命令。
https://stackoverflow.com/questions/16410817
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