我在C#项目中使用SQL数据库,我想让多个用户可以访问它 . 我已经检查过,它确实处于多用户模式,但我仍然收到一个错误,告诉我我无法连接同一个数据库中的多个用户 . 有谁知道我能做些什么来解决它?可能是代码有问题吗?

Linq的数据库访问:

var queryline = from anmeldung in context.Accounts
                            where anmeldung.Benutzername == BN
                            where anmeldung.Passwort == PW
                            select anmeldung.Id;

App.config中:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <configSections>
    </configSections>
    <connectionStrings>
        <add name="DBtest.Properties.Settings.TestConnectionString" connectionString="Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Test.mdf;Integrated Security=True;Connect Timeout=10"
            providerName="System.Data.SqlClient" />
    </connectionStrings>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
    </startup>
</configuration>

错误信息:

System.Data.SqlClient.SqlException HResult = 0x80131904 Nachricht =连接到SQL Server时与网络相关或特定于实例的错误 . 找不到或无法访问服务器 . 验证实例名称是否正确以及SQL Server是否允许远程连接..(提供者:命名管道提供程序,错误:40 - Verbindung mit SQL Server konntenichtgeöffnetwerden)Quelle = .Net SqlClient数据提供程序Stapelüberwachung:bei System.Data . SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity标识,SqlConnectionString connectionOptions,SqlCredential凭证,Object providerInfo,String newPassword,SecureString newSecurePassword,Boolean redirectedUserInstance,SqlConnectionString userConnectionOptions,SessionData reconnectSessionData,DbConnectionPool pool,String accessToken,Boolean applyTransientFaultHandling)bei System.Data.SqlClient . SqlConnectionFactory.CreateConnection(DbConnectionOptions选项,DbConnectionPoolKey poolKey,Object poolGroupProviderInfo,DbConnectionPool池,DbConnection owningConnection,DbConnectionOptions userOptions)bei System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool池) ,DbConnection owningObject,DbConnectionOptions选项,DbConnectionPoolKey poolKey,DbConnectionOptions userOptions)bei System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject,DbConnectionOptions userOptions,DbConnectionInternal oldConnection)bei System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject,DbConnectionOptions userOptions, DbConnectionInternal oldConnection)bei System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject,UInt32 waitForMultipleObjectsTimeout,Boolean allowCreate,Boolean onlyOneCheckConnection,DbConnectionOptions userOptions,DbConnectionInternal&connection)bei System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject,TaskCompletionSource1 retry,DbConnectionOptions userOptions,DbConnectionInternal&connection)bei System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection,TaskCompletionSource1 retry,DbCon nectionOptions userOptions,DbConnectionInternal oldConnection,DbConnectionInternal&connection)bei System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection,DbConnectionFactory connectionFactory,TaskCompletionSource1 retry,DbConnectionOptions userOptions)bei System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection,DbConnectionFactory connectionFactory,TaskCompletionSource1 retry,DbConnectionOptions userOptions)bei System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource1 retry)bei System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource1 retry)bei System.Data.SqlClient.SqlConnection.Open()bei System.Data . Linq.SqlClient.SqlConnectionManager.UseConnection(IConnectionUser user)bei System.Data.Linq.SqlClient.SqlProvider.get_IsSqlCe()bei System.Data.Linq.SqlClient.SqlProvider.InitializeProviderMode()bei System.Data.Linq.SqlClient.SqlProvider . System.Data.Linq.Provider.IProvider . 执行(表达式查询)bei System.Data.Linq.DataQuery`1.System.Collections.Generic.IEnumerable.GetEnumerator()bei DBtest.Program.Register(Int32&ID)in \ 192.168.2.1 \ Share \ DBtest \ DBtest \ Program .cs:Zeile61 bei DBtest.Program.Main(String [] args)在\ 192.168.2.1 \ Share \ DBtest \ DBtest \ Program.cs:Zeile102 Innere Ausnahme 1:Win32Exception:DasZeitlimitfürdieSemaphore wurde erreicht