I am a beginner in C # and I intend to create a simple program to check the connection to the mysql server (in this case I am using xampp, so the connection is local).
The problem is that the connection to the mysql server does not work, so the "Can not open connection!" box pops up. I appreciate all the explanations. thank you :)
using System;
using System.Data;
using System.Data.SqlClient;
using System.Windows.Forms;
using MySql.Data.MySqlClient;
namespace WindowsFormsApp1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void btnSend_Click(object sender, EventArgs e)
{
SqlConnection cnn;
string server = "localhost";
string database = "test";
string uid = "root";
string password = ""; //im using xampp
string connectionString;
connectionString = "SERVER=" + server + ";" + "DATABASE=" +
database + ";" + "UID=" + uid + ";" + "PASSWORD=" + password + ";";
MySqlConnection connection = new MySqlConnection(connectionString);
cnn = new SqlConnection(connectionString);
try
{
cnn.Open();
MessageBox.Show("Connection Open ! ");
cnn.Close();
}
catch (Exception ex)
{
MessageBox.Show("Can not open connection ! ");
}
}
private void button1_Click(object sender, EventArgs e)
{
this.Close();
}
}
}
Thank you for clarifying the specific problem you're having. That's helpful ;)
Thank you, too, for posting the error message.
In the future, please copy/paste the error as TEXT, not an image.
In this case, it would have been nice to run the error text through Google Translate ;)
THE PROBLEM:
Based on the error message, it sounds like your C# program might be trying to use the SQL Server driver to talk to a MySQL database. That won't work :)
SUGGESTION:
Look at any of these links:
MySQL Connector/Net Developer Guide
MySQL C# tutorial
Connect C# to MySQL
At a minimum, you'll also need to get the MySQL driver (e.g. from NuGet):
how to get new mysql connector for c#
I have the same problem after a while i find out i can not use SqlConnection. SqlConnection is for SQL Server i need to install MySql.Data from NuGet:
Install-Package MySql.Data in your Package Manager Console
then i can create MySqlConnection object and connect to your database:
System.Data.IDbConnection cnn = new MySql.Data.MySqlClient.MySqlConnection("my Connection String");
try
{
cnn.Open();
MessageBox.Show("Connection Open ! ");
cnn.Close();
}
Related
Probably the worst part about using Microsoft Access and SQL is trying to connect through the OLEDB connection. The code is on the one drive and has been working without issue but this morning it has came up with this error;
"System.InvalidOperationException: 'The 'Microsoft.ACE.OLEDB.12.0' provider is not registered on the local machine.'"
Previously I was able to change the CPU from any to x86 which sometimes seemed to fix the problem but now it is not. I am running System.Data.OleDb 7.0.0 which I have not changed since starting this protect.
using System.Data.OleDb;
using System.Data;
using System;
namespace LOGIN_TAKE_FIVE
{
public partial class Form1 : Form
{
OleDbConnection connection = new OleDbConnection();
public Form1()
{
InitializeComponent();
connection.ConnectionString = (#"Provider=Microsoft.ACE.OLEDB.12.0; Data Source=C:/Users/kiera/LOGIN TAKE FIVE/bin/Debug/net6.0-windows/dbNumber2.accdb");
}
private void btnAdd_Click(object sender, EventArgs e)
{
connection.Open();
OleDbCommand cmd = new OleDbCommand();
string encryptUser = EncryptString(tbUsername.Text);
string encryptPassword = EncryptString(tbPassword.Text);
string regSQL = "INSERT INTO Users ([Username], [Password]) VALUES ('" + encryptUser + "', '" + encryptPassword + "')";
cmd = new OleDbCommand(regSQL, connection);
cmd.ExecuteNonQuery();
connection.Close();
}
this code was working in full no less than 5 days ago so I am unsure what the problem is. Any help would be greatly appreciated.
How can I connect to a remote or local database using simple SqlConnection object? I learned to do it this way, but my connection is failing. I read about creation of connection string from this page:
https://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection.connectionstring(v=vs.110).aspx
My code:
using System.Data.SqlClient;
namespace SyncApp_BuiltInProviders
{
public partial class Form1 : Form
{
private void btnSynchronize_Click(object sender, EventArgs e)
{
SqlConnection source_conn = new SqlConnection();
source_conn.ConnectionString ="Server=localhost;Database = ptls; UID = root;Password = ODYSSEY99GRANITE;";
source_conn.Open();
}
}
}
As from your comment in another answer it is clear that you are using the wrong classes. The SqlConnection is a class specialized in connecting to Sql Server/Sql Server Express/LocalDb. It cannot work against a MySql
If you use MySql then you need to download and install the MySql Connector for NET from here.
After that, you need to reference the MySql.Data.dll and add a
using MySql.Data.MySqlClient;
to all the source files that interact with the database.
Finally, all the classes used to work with the database, should be the ones provided by the MySql NET Connector.
They are prefixed with MySql..... (MySqlConnection, MySqlCommand, MySqlDataReader etc.)
If you are used SQL Database, it seems to me that, you have not set username and password. If you have not set username and password then try this.
private void btnSynchronize_Click(object sender, EventArgs e)
{
SqlConnection db_connect= new SqlConnection();
db_connect.ConnectionString ="Server=[your local pc connection name, it is not local host.];Database=[database_name];Trusted_Connection=true";
db_connect.Open();
}
If you use MySql then
private void btnSynchronize_Click(object sender, EventArgs e)
{
//Create a MySQL connection string.
string connectionString="Server=localhost;Database[database_name];Uid=root;Password =your password; ";
MySqlConnection db_connect= new MySqlConnection(connectionString);
db_connect.Open();
}
Finally use following name space
using MySql.Data.MySqlClient;
Below is the code I used to try to connect to a remote MySQL server. I've connected to this server with a Python script using pymysql but I am unable to connect to it with Visual Studios. The application is "fully trusted" in visual studios. When I run this, I get System.InvalidOperationException stating an internal connection fatal error.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
using System.Data.SqlClient;
namespace Rextester
{
public class Program
{
public static void Main(string[] args)
{
//Your code goes here
Console.WriteLine("Hello, world!!");
SqlConnection myConnection = new SqlConnection("User ID={UserID};" +
"password={Password};Data Source=sql9.freesqldatabase.com, 3306;" +
"Trusted_Connection=yes;" +
"Initial Catalog=sql9159612; " +
"connection timeout=30");
try
{
myConnection.Open();
Console.WriteLine("Opened connection");
}
catch(Exception e)
{
Console.WriteLine("Can't open connection");
Console.WriteLine(e.ToString());
}
}
}
}
First, you'll want to download the MySql.Data package from Nuget.
Then take out ",3306" from the Data Source, and also remove the Trusted_Connection element...
var myConnection = new MySqlConnection("User ID={UserId};" +
"password={Password};Data Source=sql9.freesqldatabase.com;" +
"Initial Catalog={database}; " +
"connection timeout=30");
(I remove some of the sensitive information, fyi...)
I am very new in C# and now try to find online resource to connect VS C# to mySQL database at server 'localhost', with userid 'root', and password '****', the databasename is 'dlht'.
1.I copied a line of code from youtube and it works:
this.stockTableAdapter.Fill(this.blhsDataSet.stock);
Can anyone explain to me what exactly this is doing? There is no place to put server, password, userid etc... How can it work?
I tried to use the online tutorials to connect to mySQL database
ZetCode C#Tutorial
string cs = #"server=localhost;userid=root;
password=****;database=dlht";
MySqlConnection conn = null;
try
{
conn = new MySqlConnection(cs);
conn.Open();
Console.WriteLine("MySQL version : {0}", conn.ServerVersion);
} catch (MySqlException ex)
{
Console.WriteLine("Error: {0}", ex.ToString());
} finally
{
if (conn != null)
{
conn.Close();
}
}
I run this code at Form1.cs at VS C#. It is always stuck at :
conn = new MySqlConnection(cs);
Why? Thank you so much!
It seems that the proper way to connect to MySql database is this
Server=myServerAddress;Database=myDataBase;Uid=myUsername;Pwd=myPassword;
I Am Trying to create a program using c# that needs to connect to a database running on a Solaris server, I am not too familiar with the server, we normally use dbVisualizer to connect to it. the driver it uses to connect is mysql-connector-java-5.1.10, which is a jdbc driver. was wondering what drivers to use to connect to the database using C# and what is the syntax used to establish the connection. as far as I know I will be unable to install any drivers on the server side, and i will only be able to make changes/Install what is required on the client.
If I read your question correctly you are trying to connect to a MySql database from c#. This can be achieved by downloading the .net connector for MySql - Connector/Net. When you install this driver it will "integrate" with Visual Studio and you will be able to connect to the server directly from Visual Studio and your Program that will use the driver.
On the question on the syntax to connect you will either need to use MySqlConnection, with a tutorial here - http://bitdaddys.com/MySQL-ConnectorNet.html, or use something like the ADO.NET Entity Framework. But that depends on your Tastes.
I am assuming this Server can be access over the network.
Update User Confused about Connection String
Server=myServerAddress;Database=myDataBase;Uid=myUsername;Pwd=myPassword;
You pass that string to the connection without any JDBC:// prefixes.
Please Note haven't done this in a while so the connection string could be wrong (So correct me If I'm wrong) and if you forget any connection string in the future you can always use a website like http://www.connectionstrings.com/ which shows them all for you. That is where I got the string above.
Hope that helps.
I believe this is what you want to connect (on the server):
http://dev.mysql.com/downloads/connector/net/1.0.html
You can try your connection like this:
string MyConString = "SERVER=yourserver;" +
"DATABASE=mydatabase;" +
"UID=testuser;" +
"PASSWORD=testpassword;";
MySqlConnection connection = new MySqlConnection(MyConString);
You would probably want to follow the normal guidelines for IDisposable classes (use using etc.).
using MySql.Data.MySqlClient;
using System.Windows;
class Connexion
{
public MySql.Data.MySqlClient.MySqlConnection connexion;
private string server;
private string database;
private string uid;
private string password;
public Connexion()
{
server = "localhost";
database = "GestionCommeriale";
uid = "root";
password = "";
String connexionString;
connexionString = "SERVER=" + server + ";" + "DATABASE=" + database + ";" +
"UID" + uid + ";" + "PASSSWORD =" + password + ";";
connexion = new MySqlConnection(connexionString);
}
public bool OpenConnexion()
{
try
{
connexion.Open();
return true;
}
catch (MySqlException ex)
{
switch (ex.Number)
{
case 0:
MessageBox.Show("Cannot connect to server. Contact administrator");
break;
case 1045:
MessageBox.Show("Invalid username/password, please try again");
break;
}
return false;
}
}
public bool ColseConnexion()
{
try
{
connexion.Close();
return true;
}
catch (MySqlException ex)
{
MessageBox.Show(ex.Message);
return false;
}
}
}
}