如何通过外部主机连接到数据库？答案

【问题标题】：How to connect to a database via an external host?如何通过外部主机连接到数据库？
【发布时间】：2014-09-08 08:21:19
【问题描述】：

我做了一个简单的asp.net c#网站连接到数据库，我把文件上传到了一些托管网站，但是我得到了很长的错误信息：

error System.Data.SqlClient.SqlException (0x80131904)：建立与 SQL Server 的连接时发生与网络相关或特定于实例的错误。服务器未找到或无法访问。验证实例名称是否正确以及 SQL Server 是否配置为允许远程连接。（提供程序：SQL 网络接口，错误：52 - 无法找到本地数据库运行时安装。验证 SQL Server Express 已正确安装并且本地数据库运行时功能已启用。）---> System.ComponentModel.Win32Exception (0x80004005 ): 系统在System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(SqlException异常, Boolean breakConnection, Action1 wrapCloseInAction) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) at System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, Boolean withFailover) at System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean ignoreSniOpenTimeout, TimeoutTimer timeout, Boolean withFailover) at System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString connectionOptions, SqlCredential credential, TimeoutTimer timeout) at System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(TimeoutTimer timeout, SqlConnectionString connectionOptions, SqlCredential credential, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance) at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData) at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions) at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions) at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection) at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection) at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection) at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection) 处找不到指定的文件DbConnection owningConnection, TaskCompletionSource1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection) at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource1 retry, DbConnectionOptions userOptions) at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource1 retry, DbConnectionOptions userOptions) at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource1 retry) at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource` 1 次重试）在 ASP.default_aspx.Page_ 的 System.Data.SqlClient.SqlConnection.Open() Load(Object sender, EventArgs e) ClientConnectionId:00000000-0000-0000-0000-000000000000

【问题讨论】：

标签： c# asp.net database

【解决方案1】：

您的错误消息指出：

找不到本地数据库运行时安装。验证 SQL Server Express 是否已正确安装并且本地数据库运行时功能是否已启用

您确定那台机器上正在运行 SQL 服务器吗？您是否正确配置了连接字符串？

【讨论】：

使用我正在使用与托管站点相同的sql server：sql server 2012。并且connectionString是正确的
这是否意味着您在托管站点上安装了 SQL Server？
不，在 Visual Studio 2013 中，我使用的是 sql server 2012，当我创建数据库时，我选择了 sql server 2012，所以我确定这不是 sql server 错误。
如果 SQL Server 没有安装在那个特定的机器上，恐怕无论如何你都无法在那里创建数据库。如果那里有远程桌面，请验证是否安装了 SQL Server。单击开始按钮并转到搜索并键入不带引号的“services.msc”。然后检查是否有名称为SQL SERVER(SQLEXPRESS) 的服务以及是否处于活动状态。
我检查了它并且它是活跃的

【解决方案2】：

我解决了，在page_load的default.aspx页面中：

protected void Page_Load(object sender, EventArgs e)

(SqlConnection con)的参数内

SqlConnection con = new SqlConnection("")

有本地数据库的连接字符串，但我修好了，而是放了外部数据库的连接字符串。

【讨论】：