MySql doesn't work in Visual Studio 2012 : The type or namespace name 'MySql' could not be found

Question

Given this code :

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
//Include mysql client namespace.

using MySql.Data.MySqlClient;   // That one doesn't work !!!
using System.Configuration;

namespace CSharpMySqlSample
{
    public partial class frmMySqlSample : Form
    {
        //Read connection string from application settings file
        string   ConnectionString = ConfigurationSettings.AppSettings["ConnectionString"];
        MySqlConnection connection;
        MySqlDataAdapter adapter;
        DataTable DTItems;
        public frmMySqlSample()
        {
            InitializeComponent();
        }

        private void frmMySqlSample_Load(object sender, EventArgs e)
        {
            //Initialize mysql connection
            connection = new MySqlConnection(ConnectionString);

            //Get all items in datatable
            DTItems = GetAllItems();

            //Fill grid with items
            dataGridView1.DataSource = DTItems;
        }

        //Get all items from database into datatable
        DataTable GetAllItems()
        {
            try
            {
                //prepare query to get all records from items table
                string query = "select * from items";
                //prepare adapter to run query
                adapter = new MySqlDataAdapter(query, connection);
                DataSet DS = new DataSet();
                //get query results in dataset
                adapter.Fill(DS);

                // Set the UPDATE command and parameters.
                adapter.UpdateCommand = new MySqlCommand(
                    "UPDATE items SET ItemName=@ItemName, Price=@Price, AvailableQuantity=@AvailableQuantity, Updated_Dt=NOW() WHERE ItemNumber=@ItemNumber;",
                    connection);
                adapter.UpdateCommand.Parameters.Add("@ItemNumber", MySqlDbType.Int16, 4, "ItemNumber");
                adapter.UpdateCommand.Parameters.Add("@ItemName", MySqlDbType.VarChar, 100, "ItemName");
                adapter.UpdateCommand.Parameters.Add("@Price", MySqlDbType.Decimal, 10, "Price");
                adapter.UpdateCommand.Parameters.Add("@AvailableQuantity", MySqlDbType.Int16, 11, "AvailableQuantity");
                adapter.UpdateCommand.UpdatedRowSource = UpdateRowSource.None;

                // Set the INSERT command and parameter.
                adapter.InsertCommand = new MySqlCommand(
                    "INSERT INTO items VALUES (@ItemNumber,@ItemName,@Price,@AvailableQuantity,NOW());",
                    connection);
                adapter.InsertCommand.Parameters.Add("@ItemNumber", MySqlDbType.Int16, 4, "ItemNumber");
                adapter.InsertCommand.Parameters.Add("@ItemName", MySqlDbType.VarChar, 100, "ItemName");
                adapter.InsertCommand.Parameters.Add("@Price", MySqlDbType.Decimal, 10, "Price");
                adapter.InsertCommand.Parameters.Add("@AvailableQuantity", MySqlDbType.Int16, 11, "AvailableQuantity");
                adapter.InsertCommand.UpdatedRowSource = UpdateRowSource.None;

                // Set the DELETE command and parameter.
                adapter.DeleteCommand = new MySqlCommand(
                    "DELETE FROM items "
                    + "WHERE ItemNumber=@ItemNumber;", connection);
                adapter.DeleteCommand.Parameters.Add("@ItemNumber",
                  MySqlDbType.Int16, 4, "ItemNumber");
                adapter.DeleteCommand.UpdatedRowSource = UpdateRowSource.None;

                //return datatable with all records
                return DS.Tables[0];
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            return null;
        }

        private void btnSave_Click(object sender, EventArgs e)
        {
            try
            {
                //Save records in database using DTItems which is datasource for Grid
                adapter.Update(DTItems);
                //Refresh grid
                DTItems = GetAllItems();
                dataGridView1.DataSource = DTItems;
                MessageBox.Show("Items saved successfully...");
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void btnDelete_Click(object sender, EventArgs e)
        {
            if (dataGridView1.SelectedRows.Count > 0)
            {
                //Delete a row from grid first.
                dataGridView1.Rows.Remove(dataGridView1.SelectedRows[0]);

                //Save records again. This will delete record from database.
                adapter.Update(DTItems);

                //Refresh grid. Get items again from database and show it in grid.
                DTItems = GetAllItems();
                dataGridView1.DataSource = DTItems;
                MessageBox.Show("Selected item deleted successfully...");
            }
            else
            {
                MessageBox.Show("You must select entire row in order to delete it.");
            }
        }
    }
}

After compilation I get :

error CS0246: The type or namespace name 'MySqlConnection' could not be found (are you missing a using directive or an assembly reference?)

But I checked the connector :

And it's installed ..

So what's wrong ?

Thanks

Solution 1

You need to add reference to MySql.Data.dll but it is better you can add this dll as package by using NuGet

below is the Package Manager Console command

PM> Install-Package MySql.Data

Solution 2

Add a reference from the project to the MySql.Data.dll as well.

using doesn't make assemblies available. It only allows you to use entries from a namespace without specifying that namespace each time.

Solution 3

You must add it as a reference

Solution 4

We'll be adding support for VS 2012 in Connector/NET 6.5.5 and later 6.6.x version http://forums.mysql.com/read.php?38,546265,564533#msg-564533

and give a link to test a trick

http://social.technet.microsoft.com/wiki/pt-br/contents/articles/10476.instalando-mysql-connector-no-visual-studio-2011-beta.aspx

Refer this answer

Solution 5

Just an idea,

Looks like you're missing MySql.Data in your project which you can declare in your web.config

Make sure you have your web.config properly configured.

 <assemblyIdentity name="MySql.Data" publicKeyToken="c5687fc88969c44d" culture="neutral" />
 <assemblyIdentity name="MySql.Web" publicKeyToken="c5687fc88969c44d" culture="neutral" />

View more solutions

Comments

[Angel M.]

Thanks a lot, this is the only thing that work on my Ubuntu

[Charitha Goonewardena]

after installing this add this one from browse which is located under the add reference panel

[AStopher]

@CharithaGoonewardena Shouldn't need to do that.

[AStopher]

Note that this isn't a web project so there will be no web.config file, but good advice for future reference.