Unable to connect to any of the specified mysql hosts. C# MySQL

Question

I am getting the above error when I execute the code -

MySqlConnection mysqlConn=new MySqlConnection("server=127.0.0.1;uid=pankaj;port=3306;pwd=master;database=patholabs;");

mysqlConn.Open();

I have also tried setting server to localhost, user to root but I am getting the below error- 

Error: 0 : Unable to connect to any of the specified MySQL hosts.

System.Transactions Critical: 0 : <TraceRecord xmlns="http://schemas.microsoft.com/2004/10/E2ETraceEvent/TraceRecord" Severity="Critical"><TraceIdentifier>http://msdn.microsoft.com/TraceCodes/System/ActivityTracing/2004/07/Reliability/Exception/Unhandled</TraceIdentifier><Description>Unhandled exception</Description><AppDomain>DBSync.exe</AppDomain><Exception><ExceptionType>MySql.Data.MySqlClient.MySqlException, MySql.Data, Version=6.7.4.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d</ExceptionType><Message>Unable to connect to any of the specified MySQL hosts.</Message><StackTrace>

at  MySql.Data.MySqlClient.NativeDriver.Open()

at MySql.Data.MySqlClient.Driver.Open()

at MySql.Data.MySqlClient.Driver.Create(MySqlConnectionStringBuilder settings)

at MySql.Data.MySqlClient.MySqlPool.CreateNewPooledConnection()

at MySql.Data.MySqlClient.MySqlPool.GetPooledConnection()

at MySql.Data.MySqlClient.MySqlPool.TryToGetDriver()

at MySql.Data.MySqlClient.MySqlPool.GetConnection()

at MySql.Data.MySqlClient.MySqlConnection.Open()

at DBSync.MainForm.BtnCalculateClick(Object sender, EventArgs e) in c:\Documents  and Settings\Test01\My Documents\SharpDevelop Projects\DBSync\DBSync\MainForm.cs:line 51

at System.Windows.Forms.Control.OnClick(EventArgs e)

at System.Windows.Forms.Button.OnClick(EventArgs e)

at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)

at System.Windows.Forms.Control.WmMouseUp(Message&amp;amp; m, MouseButtons button, Int32 clicks)

at System.Windows.Forms.Control.WndProc(Message&amp;amp; m)

at System.Windows.Forms.ButtonBase.WndProc(Message&amp;amp; m)

at System.Windows.Forms.Button.WndProc(Message&amp;amp; m)

at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message&amp;amp; m)

at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message&amp;amp; m)

at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG&amp;amp; msg)

at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)

at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)

at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)

at System.Windows.Forms.Application.Run(Form mainForm)

at DBSync.Program.Main(String[] args) in c:\Documents and Settings\Test01\My Documents\SharpDevelop Projects\DBSync\DBSync\Program.cs:line 27</StackTrace><ExceptionString>MySql.Data.MySqlClient.MySqlException (0x80004005): Unable to connect to any of the specified MySQL hosts.

at MySql.Data.MySqlClient.NativeDriver.Open()

at MySql.Data.MySqlClient.Driver.Open()

at MySql.Data.MySqlClient.Driver.Create(MySqlConnectionStringBuilder settings)

at MySql.Data.MySqlClient.MySqlPool.CreateNewPooledConnection()

at MySql.Data.MySqlClient.MySqlPool.GetPooledConnection()

at MySql.Data.MySqlClient.MySqlPool.TryToGetDriver()

at MySql.Data.MySqlClient.MySqlPool.GetConnection()

at MySql.Data.MySqlClient.MySqlConnection.Open()

at DBSync.MainForm.BtnCalculateClick(Object sender, EventArgs e) in c:\Documents and Settings\Test01\My Documents\SharpDevelop Projects\DBSync\DBSync\MainForm.cs:line 51

at System.Windows.Forms.Control.OnClick(EventArgs e)

at System.Windows.Forms.Button.OnClick(EventArgs e)

at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)

at System.Windows.Forms.Control.WmMouseUp(Message&amp;amp; m, MouseButtons button, Int32 clicks)

at System.Windows.Forms.Control.WndProc(Message&amp;amp; m)

at System.Windows.Forms.ButtonBase.WndProc(Message&amp;amp; m)

at System.Windows.Forms.Button.WndProc(Message&amp;amp; m)

at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message&amp;amp; m)

at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message&amp;amp; m)

at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG&amp;amp; msg)

at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)

at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)

at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)

at System.Windows.Forms.Application.Run(Form mainForm)

at DBSync.Program.Main(String[] args) in c:\Documents and Settings\Test01\My Documents\SharpDevelop Projects\DBSync\DBSync\Program.cs:line 27</ExceptionString><DataItems><Data><Key>Server Error Code</Key><Value>1042</Value></Data></DataItems></Exception></TraceRecord>

When I try I can be able to connect to the MySQL server through the MySQL Workbench and I can also query the database. It is only the code that is not working.

Answer 1

In some of the ways, spacing and the order of parameters in the connection string does matters (based on the personal experience).

So stick to the standard format here.

Server=myServerAddress; Port=1234; Database=myDataBase; Uid=myUsername; Pwd=myPassword;

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