.net MySQL/ MariaDB Class

[ecks de]

VB.NET:

 Spoiler

Imports MySql
Imports MySql.Data
Imports MySql.Data.MySqlClient

Public Class MySQL
    ' Class to connect and start mysql queries
    '###########################################

    ' Attributes
    Private dbConnection As MySqlConnection
    Private serverFeedback As DataTable = Nothing
    Private connectionString As String = "server=;uid=;pwd=;database=;"
    Public query As String

    Public parameters As New List(Of String)


    ''' <summary>
    ''' Creates a mysql instance and connection through official mysql lib
    ''' </summary>
    Sub New()
        dbConnection = New MySqlConnection
        dbConnection.ConnectionString = connectionString
        Try
            dbConnection.Open()
        Catch ex As Exception
            MessageBox.Show("Error", "MySQL Connection failed!" + vbNewLine + ex.Message, MessageBoxButtons.OK, icon:=MessageBoxIcon.Error)
        End Try

    End Sub

    ''' <summary>
    ''' Executes query and saves the feedback in *serverFeedback*
    ''' </summary>
    Public Function executeQuery() As Boolean
        Dim cmd As New MySqlCommand(query, dbConnection)
        'Parameter binding
        Dim i As Integer = 0
        For Each parameter As String In Me.parameters
            cmd.Parameters.AddWithValue(i.ToString(), parameter)
            i += 1
        Next
        'Execute Query
        Try
            'Get and write response
            Dim da As New MySqlDataAdapter(cmd)
            Dim ds As New DataSet()
            da.Fill(ds, 0)
            If ds.Tables.Count > 0 Then
                Dim dt As DataTable = ds.Tables(0)
                serverFeedback = dt
            Else
                serverFeedback = Nothing
            End If
            Return True
        Catch ex As Exception
            MessageBox.Show(String.Format("MySQL Query Execute failed!{0}{1}", vbNewLine, ex.Message), "Error", MessageBoxButtons.OK, icon:=MessageBoxIcon.Error)
            Return False
        End Try
    End Function

    ''' <summary>
    ''' Attribute return function
    ''' </summary>
    ''' <returns>Server feedback as a DataTable</returns>
    Public Function getServerReturn()
        Return serverFeedback
    End Function

    ''' <summary>
    ''' Closes MySQL Connection. Object not usable after calling this!
    ''' </summary>
    Public Sub closeConnection()
        dbConnection.Close()
        Me.Finalize()
    End Sub
End Class

C#:

 Spoiler

using MySql.Data.MySqlClient;
public class MySQL {
    
    //  Class to connect and start mysql queries
    // ###########################################
    //  Attributes
    private MySqlConnection dbConnection;
    
    private DataTable serverFeedback = null;
    
    private const string connectionString = "server=;uid=;pwd=;database=;";
    
    public string query;
    
    public List<string> parameters = new List<string>();
    
    MySQL() {
        dbConnection = new MySqlConnection();
        dbConnection.ConnectionString = connectionString;
        try {
            dbConnection.Open();
        }
        catch (Exception ex) {
            MessageBox.Show("Error", ("MySQL Connection failed!" + ("\r\n" + ex.Message)), MessageBoxButtons.OK, MessageBoxIcon.Error);
            
        }
        
    }
    
    // '' <summary>
    // '' Executes query and saves the feedback in *serverFeedback*
    // '' </summary>
    public bool executeQuery() {
        MySqlCommand cmd = new MySqlCommand(query, dbConnection);
        // Parameter binding
        int i = 0;
        foreach (string parameter in this.parameters) {
            cmd.Parameters.AddWithValue(i.ToString(), parameter);
            i++;
        }
        
        // Execute Query
        try {
            // Get and write response
            MySqlDataAdapter da = new MySqlDataAdapter(cmd);
            DataSet ds = new DataSet();
            da.Fill(ds, 0);
            if ((ds.Tables.Count > 0)) {
                DataTable dt = ds.Tables[0];
                serverFeedback = dt;
            }
            else {
                serverFeedback = null;
            }
            
            return true;
        }
        catch (Exception ex) {
            MessageBox.Show(string.Format("MySQL Query Execute failed!{0}{1}", "\r\n", ex.Message), "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
           
            return false;
        }
        
    }
    
    // '' <summary>
    // '' Attribute return function
    // '' </summary>
    // '' <returns>Server feedback as a DataTable</returns>
    public void getServerReturn() {
        return serverFeedback;
    }
    
    // '' <summary>
    // '' Closes MySQL Connection. Object not usable after calling this!
    // '' </summary>
    public void closeConnection() {
        dbConnection.Close();
        this.Finalize();
    }
}

You need this MySQL Connector:

[Serraniel]

I just have checked the C# code but I assume the VB.Net may work the same. So here is some feedback about several issues I noticed by quickly scanning your code:

1: In sense to use this class as a MySQL wrapper you should be able to pass the connection data through the constructor and building the connection string dynamically instead of defining them during compile time and using the pre defined connection string.

2: Do not catch an exception and show a message box with the error in a class you may want to spread. In general, this type of error handling belongs to the developer who wants to use your lib.

3: Same for the query as for the constructor. Pass the query as parameter so it can be used for any query.

4: Instead of the closeConnection you should implement interface.

[ecks de]

Originally Posted by Serraniel

I just have checked the C# code but I assume the VB.Net may work the same. So here is some feedback about several issues I noticed by quickly scanning your code:

1: In sense to use this class as a MySQL wrapper you should be able to pass the connection data through the constructor and building the connection string dynamically instead of defining them during compile time and using the pre defined connection string.

2: Do not catch an exception and show a message box with the error in a class you may want to spread. In general, this type of error handling belongs to the developer who wants to use your lib.

3: Same for the query as for the constructor. Pass the query as parameter so it can be used for any query.

4: Instead of the closeConnection you should implement interface.

Ye thanks, that is actually an old version. handling exceptions and printing them is pretty bad i know, but it was for testing purporse only xd. thanks for feedback!

[atom0s]

This is fairly pointless/useless, to be honest. Your class does not offer any real useful features or expand off the already available features of the MySQL connector itself. There are several errors with your code as well, such as returning a value in a void function.