public class GenericSqlExecutionRepository
{
    private IDbConnection _db;

    public void RecreateDb()
    {
        _db.Execute("DROP DATABASE IF EXISTS `my_db`;");
        _db.Execute("CREATE DATABASE `my_db`;");
    }
}

"Unknown database 'my_db'"

at MySql.Data.MySqlClient.MySqlStream.ReadPacket()
at MySql.Data.MySqlClient.NativeDriver.ReadOk(Boolean read)
at MySql.Data.MySqlClient.NativeDriver.SetDatabase(String dbName)
at MySql.Data.MySqlClient.Driver.SetDatabase(String dbName)
at MySql.Data.MySqlClient.MySqlConnection.ChangeDatabase(String databaseName)
at MySql.Data.MySqlClient.MySqlConnection.Open()
at Dapper.SqlMapper.ExecuteCommand(IDbConnection cnn, CommandDefinition& command, Action`2 paramReader)
at Dapper.SqlMapper.ExecuteImpl(IDbConnection cnn, CommandDefinition& command)
at Dapper.SqlMapper.Execute(IDbConnection cnn, String sql, Object param, IDbTransaction transaction, Nullable`1 commandTimeout, Nullable`1 commandType)

public static MySqlConnection GetConnection(string connectionStringId)
{
    var connectionString = ConfigurationManager.ConnectionStrings[connectionStringId].ConnectionString;
    var connection = new MySqlConnection();
    connection.ConnectionString = connectionString;

    return connection;
}

<add name="myDbId" connectionString="Server=localhost;Port=3306;Database=xxxxxx;User=yyyyyyy;Password=zzzzzzz;Convert Zero Datetime=True;Compress=True;" providerName="System.Data.SqlClient"/>