c# - MySQL "network-related or instance-specific error occurred while establishing a connection to SQL Server"

Question

I've been looking around for a solution to this issue and the only one that might provide a solution is the only one I haven't tried, because it involves changing system properties. I want to avoid that if I can.

The Connection string is correct, but it still won't connect.

The exception occurs on line 30, which is where the connection string is opened. conn.Open()

Here is the Code:

using System.Text;
using System.Data.SqlClient;

namespace My_Sql_Program
{
    class Program
    {
        static void Main()
        {
            try
            {
                // Step 1: Create a SqlConnection Object to connect to the 
                // SQL Northwind database.
                SqlConnection conn = new SqlConnection("server=localhost;database=dcim;uid=root;pwd=LlmD62jL");

                // Step 2: Create a SqlCommand object.
                SqlCommand cmd = conn.CreateCommand();

                // Step 3: Set the CommandText property of the SqlCommand object to a 
                // SQL SELECT statment that retrieves a row from the Customers table.
                cmd.CommandText = "SELECT UserName, UserPassword, AuthorityLevel, " +
                    "FROM Users " +
                    "WHERE UserName = 'ben'";

                // Step 4: Open the database connection using the 
                // Open() method of the SqlConnection object.
                conn.Open();

                //Step 5: Create a SqlDataReader object and call the ExecuteReader()
                //Method of the SqlCommand object to run the SELECT statement.
                SqlDataReader rdr = cmd.ExecuteReader();

                // Step 6: Read the row from the SqlDataReader object using the Read() method.
                rdr.Read();

                // Step 7: Display the column values.
                Console.WriteLine("rdr["UserName"] = " + rdr["UserName"]);
                Console.WriteLine("rdr["UserPassword"] = " + rdr["UserPassword"]);
                Console.WriteLine("rdr["AuthorityLevel"] = " + rdr["AuthorityLevel"]);

                // Step 8: Close the SqlReader object using the Close() method.
                rdr.Close();

                // Step9: Close the SqlConnection object using the Close() method.
                conn.Close();
            }
            catch (SqlException e) 
            {
                Console.WriteLine("An SqlException was thrown.");
                Console.WriteLine("Number = " + e.Number);
                Console.WriteLine("Message = " + e.Message);
                Console.WriteLine("StackTrace:
" + e.StackTrace);
            }
            Console.ReadLine();
        }
    }
}

And when I run it, nothing happens for about 30 seconds, then the SqlException is printed:

An SqlException was thrown.
Number = 2
Message = 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)

StackTrace:
   at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean
breakConnection, Action`1 wrapCloseInAction)
   at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean
breakConnection, Action`1 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)
   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,
DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnectionOptions userOptions)
   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,
TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection,
TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection,
DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions
userOptions)
   at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
   at System.Data.SqlClient.SqlConnection.Open()
   at My_Sql_Program.Program.Main() in c:userspauldocumentsvisual studio 2010ProjectsMy Sql
ProgramMy Sql ProgramProgram.cs:line 30

Answer 1

SqlConnection is for SqlServer. To connect to MySql you need to download some drivers and reference it in your project, and use MySqlConnection instead.

Take a look at this question and this CodeProject sample.