Question

我最近开始为我正在处理的一些项目使用EF v4 Code Only库。但是，我遇到了一些障碍。我似乎无法弄清楚连接字符串的正确格式。我使用以下代码来构建连接字符串：

string connectionString = new EntityConnectionStringBuilder
{
    Provider = "System.Data.SqlClient",
    ProviderConnectionString = new SqlConnectionStringBuilder
    {
        DataSource = "localhost",
        InitialCatalog = "ASM_Testing",
        IntegratedSecurity = true,
        Pooling = false
    }.ConnectionString
}.ConnectionString;

但是，使用它会导致以下错误：

Specifications_for_EntityContext.When_logging_in_application_with_valid_app_role_and_password.Login_should_be_successful : System.ArgumentException : Some required information is missing from the connection string. The 'metadata' keyword is always required.
Stack Trace:
   at System.Data.EntityClient.EntityConnection.ValidateValueForTheKeyword(DbConnectionOptions effectiveConnectionOptions, String keywordName)
   at System.Data.EntityClient.EntityConnection.ChangeConnectionString(String newConnectionString)
   at System.Data.Objects.ObjectContext..ctor(String connectionString)
   at ASM.Data.EntityContext..ctor(String connectionString) in C:\Users\Jon Rista\TFS\Advanced Service Management\Trunk\Main\Source\ASM.Data\EntityContext.cs:line 16
   at Specifications_for_EntityContext.Behaves_like_EntityContext_connected_to_a_database.TestableEntityContext..ctor(String connectionString) in C:\Users\Jon Rista\TFS\Advanced Service Management\Trunk\Main\Source\Tests.ASM.Data\EntityContextFacts.cs:line 165
   at Specifications_for_EntityContext.Behaves_like_EntityContext_connected_to_a_database.InitializeContext() in C:\Users\Jon Rista\TFS\Advanced Service Management\Trunk\Main\Source\Tests.ASM.Data\EntityContextFacts.cs`e`enter code here`nter code here`:line 160
   at ASM.Testing.xUnit.ObservationCommand.Execute(Object testClass) in C:\Users\Jon Rista\TFS\Advanced Service Management\Trunk\Main\Source\ASM.Testing.xUnit\ObservationCommand.cs:line 24
   at Xunit.Sdk.FixtureCommand.Execute(Object testClass)
   at Xunit.Sdk.BeforeAfterCommand.Execute(Object testClass)
   at Xunit.Sdk.LifetimeCommand.Execute(Object testClass)
   at Xunit.Sdk.TimedCommand.Execute(Object testClass)
   at Xunit.Sdk.ExceptionAndOutputCaptureCommand.Execute(Object testClass)

因为我没有任何元数据...因为我使用的是Code Only，所以我有点绑定。非常感谢任何见解。

构建器类生成的连接字符串如下：

提供商= System.Data.SqlClient的;提供者 connection string =“数据源=本地主机;初始目录= ASM_Testing;集成安全= TRUE;池=假“

工作示例（基于已接受的答案）

有必要使用ContextBuilder创建使用仅代码模式的上下文实例。对于那些正在寻找同一问题答案的人来说，这是一个有效的例子：

protected override void InitializeContext()
{
    string connectionString = new SqlConnectionStringBuilder
    {
        DataSource = "localhost",
        InitialCatalog = "Testing",
        IntegratedSecurity = true,
        Pooling = false
    }.ConnectionString;

    var connection = new SqlConnection(connectionString);
    var builder = new ContextBuilder<TestableEntityContext>();
    m_context = builder.Create(connection);
}

Answer 1

使用它：

var builder = new ContextBuilder<YourContext>();

using (YourContext context = builder.Create(new SqlConnection(ConfigurationManager.ConnectionStrings["yourConenctionKeyInWebConfig"].ConnectionString)))
{
     ...
}

Answer 2

据我所知，只使用代码方法，您无法通过简单地将DB连接字符串传递给它的ctor来实例化上下文。通常，您可以使用ContextBuilder来创建上下文。

在EntityConnection班级
中定义EntityContext
public EntityContext（EntityConnection连接）：base（连接） { }
创建连接

var factory = DbProviderFactories.GetFactory（“System.Data.SqlClient”）; var connection = factory.CreateConnection（）; connection.ConnectionString = providerConnectionString;
使用ContextBuilder创建新的上下文

var contextBuilder = new ContextBuilder（）; contextBuilder.Configurations.Add（...） var context = contextBuilder.Create（connection）;

实体框架v4仅代码连接字符串

2 个答案: