So, in order to connect to a MySql database from VS2010 you need to

1. download the latest version of the MySql Connector/NET from http://www.mysql.com/downloads/connector/net/

2. install the connector (if you have an older version you need to remove it from Control Panel -> Add / Remove Programs)

3. open Visual Studio 2010

4. open Server Explorer Window (View -> Server Explorer)



5. use Connect to Database button

6. in the Choose Data Source windows select MySql Database and press Continue



7. in the Add Connection window
- set server name: 127.0.0.1 or localhost for MySql server running on local machine or an IP address for a remote server
- username and password
- if the the above data is correct and the connection can be made, you have the possibility to select the database



If you want to connect to a MySql database from a C# application (Windows or Web) you can use the next sequence:

//define the connection reference and initialize it
MySql.Data.MySqlClient.MySqlConnection msqlConnection = null;
msqlConnection = new MySql.Data.MySqlClient.MySqlConnection(“server=localhost;user id=UserName;Password=UserPassword;database=DatabaseName;persist security info=False”);
    //define the command reference
MySql.Data.MySqlClient.MySqlCommand msqlCommand = new MySql.Data.MySqlClient.MySqlCommand();
    //define the connection used by the command object
msqlCommand.Connection = this.msqlConnection;
    //define the command text
msqlCommand.CommandText = "SELECT * FROM TestTable;";
try
{
    //open the connection
    this.msqlConnection.Open();
    //use a DataReader to process each record
    MySql.Data.MySqlClient.MySqlDataReader msqlReader = msqlCommand.ExecuteReader();
    while (msqlReader.Read())
    {
        //do something with each record
    }
}
catch (Exception er)
{
    //do something with the exception
}
finally
{
    //always close the connection
    this.msqlConnection.Close();
}.