SqlException: System.Data.SqlClient.SqlException (0x80131904)

Question

我用 C# 编写了一个代码，它在我的计算机上运行良好，在 Windows 7 (MS SQL Server 2008) 上运行良好，但在 Windows Vista (MS SQL Server 2005) 上运行时则不然。我无法在第二台计算机上更改系统；) 我使用的是 Visual Studio 2010。

所以这是代码的一部分，来自我的课程“obSQL”：

private SqlConnection connection;

    public obSQL(string user, string pass, string instance, string dbdir) //sql server authentication
    {
        connection = new SqlConnection();
        connection.ConnectionString = "user id=" + user + ";" +
                                      "password=" + pass +
                                      ";Data Source=" + instance + ";" +
                                      "Trusted_Connection=no;" +
                                      "database=" + dbdir + "; " +
                                      "connection timeout=3"; //more at http://www.connectionstrings.com/
        connection.Open();
    }

    public obSQL(string instance, string dbdir) //windows authentication
    {
        connection = new SqlConnection();
        connection.ConnectionString = "Data Source=" + instance + ";" +
                                      "Trusted_Connection=yes;" +
                                      "database=" + dbdir + "; " +
                                      "connection timeout=3";
        connection.Open();
    }

它在我的计算机（SQL Server 2008）上运行良好。但是当我在另一个（SQL Server 2005）上运行相同的代码时，出现了一个错误（部分是其他语言，所以我为你翻译了它）：

错误 SqlException: System.Data.SqlClient.SqlException (0x80131904) : 错误 网络或连接 SQL Server 时发生错误。找不到服务器或不可用。验证实例名称是否正确以及 SQL Server 的配置是否允许远程连接。（提供者：命名管道提供程序，错误：40 - 无法打开与 SQL Server 的连接) 在 System.Data.SqlClient.SqlInternalConnection.OnError(SqlException 异常，Boolean breakConnection) 在 System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning() 在 System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, TimeoutTimer timeout, SqlConnection owningObject) 处的 Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean IntegratedSecurity) serverInfo、String newPassword、Boolean redirectedUserInstance、SqlConnection owningObject、SqlConnectionString connectionOptions、TimeoutTimer 超时）在 System.Data。SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, TimeoutTimer timeout, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance) at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, Boolean redirectedUserInstance) ) 在 System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options) at System.Data.ProviderBase .DbConnectionPool。CreateObject(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System. Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection externalConnection, DbConnectionFactory connectionFactory) at System.Data.SqlClient.SqlConnection.Open() at cennik01.obSQL..ctor(String user, String pass, String instance, String dbdir) at Cennik_v2._1 .Form1.button1_Click（对象发送者，EventArgs e）GetConnection(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection externalConnection, DbConnectionFactory connectionFactory) at System.Data.SqlClient.SqlConnection.Open() at cennik01 .obSQL..ctor(String user, String pass, String instance, String dbdir) at Cennik_v2._1.Form1.button1_Click(Object sender, EventArgs e)GetConnection(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection externalConnection, DbConnectionFactory connectionFactory) at System.Data.SqlClient.SqlConnection.Open() at cennik01 .obSQL..ctor(String user, String pass, String instance, String dbdir) at Cennik_v2._1.Form1.button1_Click(Object sender, EventArgs e)_1.Form1.button1_Click（对象发送者，EventArgs e）_1.Form1.button1_Click（对象发送者，EventArgs e）

当我运行其他使用相同数据库的程序时，它连接正确，所以我认为登录等是正确的......我希望:) 但是第二个程序是商业的，所以我没有它的源代码，我只给出他我的dbdir，实例，用户名和密码。

所以……我能做什么？

Answer 1

此错误不是登录问题。这不是无效凭据的问题。为此，您会收到不同的错误消息。此错误消息仅表示它在连接字符串中找不到服务器（可能）或数据库。

CodePlex 上有一个开源程序，您可以下载以测试连接字符串等。 您可以在此处找到它。这应该可以帮助您确定问题出在哪里/是什么。