Back

Explore Courses Blog Tutorials Interview Questions
0 votes
1 view
in SQL by (6.1k points)
edited by

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.

1 Answer

0 votes
by (12.7k points)
edited by

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;

If you want to learn more about SQL, Check out this SQL Certification by Intellipaat. 

For more information visit :

Related questions

0 votes
1 answer
0 votes
1 answer

Browse Categories

...