无法在 cs 文件中打开 sql 连接 - asp.net

Question

我是 ASP.NET 的新手，正在学习用户可以注册到站点并检查数据库以查看用户名是否已存在的教程。当创建数据库的时候，教程说在 visual studio（mdf 文件）中创建它，但我使用 MYSQL Workbench，所以我在那里创建它并尝试自己连接它.

在 Visual 中的数据连接下添加连接时，我能够看到我的数据库并且测试连接有效。

添加 SQLDataSource 时，我能够运行测试查询成功并从数据库中读取。我什至将它与 GridView 一起用于在网页上显示数据。

但是在cs文件中打开连接时出现错误。

[Win32Exception (0x80004005): The system cannot find the file specified]

[SqlException (0x80131904): A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)]
   System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) +5347119
   System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) +546
   System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, Boolean withFailover) +5358907
   System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean ignoreSniOpenTimeout, TimeoutTimer timeout, Boolean withFailover) +145
   System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString connectionOptions, SqlCredential credential, TimeoutTimer timeout) +892
   System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(TimeoutTimer timeout, SqlConnectionString connectionOptions, SqlCredential credential, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance) +311
   System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData) +646
   System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions) +278
   System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions) +38
   System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection) +732
   System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection) +85
   System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection) +1057
   System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection) +78
   System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection) +196
   System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions) +146
   System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions) +16
   System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry) +94
   System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry) +110
   System.Data.SqlClient.SqlConnection.Open() +96
   Registration.Page_Load(Object sender, EventArgs e) in e:\WebSite\Registration.aspx.cs:15
   System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +51
   System.Web.UI.Control.OnLoad(EventArgs e) +92
   System.Web.UI.Control.LoadRecursive() +54
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +772

此处代码出现错误

15 SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["RegisterCS"].ConnectionString);
16 conn.Open();//ERROR HERE

这是我的web.config，以防万一

<?xml version="1.0"?>
<!--
  For more information on how to configure your ASP.NET application, please visit
  http://go.microsoft.com/fwlink/?LinkId=169433
  -->
<configuration>
  <connectionStrings>
    <add name="RegisterCS" connectionString="server=localhost;User Id=root;password=******;database=asptest"
      providerName="MySql.Data.MySqlClient" />
  </connectionStrings>
  <system.web>
    <compilation debug="true" targetFramework="4.0"/>
  </system.web>


</configuration>

我环顾四周，显然它可能是连接字符串，但我认为应该没问题，因为数据源实际上已从数据库中成功读取，对吗？我是否缺少正确连接数据库的内容？也许我必须在 Workbench 中做些什么？我也尝试关闭防火墙。谢谢。

Answer 1

MySQL 连接字符串 Uid 和 Pwd 分别代替了 User Id 和 Password。

http://dev.mysql.com/doc/connector-net/en/connector-net-programming-connecting-connection-string.html

The following is a sample connection string:
Server=127.0.0.1;Uid=root;Pwd=12345;Database=test;
In this example, the MySqlConnection object is configured to connect to a MySQL server at 127.0.0.1, with a user name of root and a password of 12345. The default database for all statements will be the test database.

此外，评论讨论导致 Port 不是 3306 的 standard/default，而是 5354。因此连接字符串应如下所示：

Server=localhost;Uid=root;Pwd=******;Database=asptest;Port=5354

此外，您可能不需要将User Id更改为Uid，将Password更改为Pwd，文档对于选项允许以下内容：

Password, pwd; The password for the MySQL account being used.

User Id, UserID, Username, Uid, User name, User: The MySQL login account being used.

http://dev.mysql.com/doc/connector-net/en/connector-net-connection-options.html

最后，您需要 MySQL 连接器。那么您需要将 SqlConnections 换成 MySqlConnections.

无法在 cs 文件中打开 sql 连接 - asp.net

Can't open sql connection in cs file - asp.net

c#

mysql

asp.net

database

localhost