I can't connect to my MySql database via my C# cmd it gets me error 1042
this code is from:
http://social.msdn.microsoft.com/Forums/vstudio/en-US/67226fe6-175a-4f8b-96ab-a22fd836617f/inserting-values-to-mysql-using-c
using System;
using System.Diagnostics;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using MySql.Data.MySqlClient;
class MyClass
{
public static void Main()
{
MySqlConnection conn = new MySql.Data.MySqlClient.MySqlConnection();
MySqlCommand cmd = new MySql.Data.MySqlClient.MySqlCommand();
string SQL;
conn.ConnectionString = "server=SERVER; userid=USER;password=PASSWORD;database=DATABASE;";
try
{
conn.Open();
MessageBox.Show("Files Inserted into database successfully!",
"Success!", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
conn.Close();
}
catch (MySql.Data.MySqlClient.MySqlException ex)
{
MessageBox.Show("Error " + ex.Number + " has occurred: " + ex.Message,
"Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
}
UPDATE - SOLVED
SOLVED the server name was a bad url
i used
db4free.net
maybe the dash in my host was the problem
MySQL error 1042 (HY000) is reported from the MySQL server when it can't resolve the client IP address into a hostname.
On our MySQL servers, we disable hostname resolution, and use IP addresses instead.
If you don't want to disable hostname resolution, then you need to ensure that MySQL can resolve your client IP address into a hostname, either by adding an appropriate entry to the /etc/hosts file (on the MySQL server host), or adding an appropriate entry to the DNS server(s).
Otherwise, you can disable hostname resolution by adding skip-name-resolve in the [mysqld] section of the MySQL server configuration file (and restarting the MySQL server). NOTE: Any current users defined using a hostname won't be able available, since MySQL will now be looking (defined in the mysql.users table) for users of the form "foo#192.168.1.33", rather than "foo#tyrion", and MySQL isn't going to find a match. (This isn't a problem if your users are all defined with the % wildcard as the hostname.)
I was facing same issue,i was tring to connect to remnote mysql server using my window 7 os machine but in my case disabling firewall solved my problem
Related
I am using this code but getting an error of 'Object reference not set to an instance of an object.' at con.open() ? what am I doing wrong ?
I have already download and installed ODAC component version 10 , 11 ,12 trying each one at the failure of the latest one but still same error
using Oracle.DataAccess.Client;
namespace WindowsFormsApplication1
{
class OraTest
{
public OracleConnection con = new OracleConnection();
public void Connect()
{
con.ConnectionString = "Data Source=(DESCRIPTION= (ADDRESS = (PROTOCOL = TCP)(HOST =myip) (PORT = myport))(CONNECT_DATA = (SERVER = dedicated)(SERVICE_NAME = mydb)));User ID=myid;Password=mypass;";
con.Open(); //error here
}
public void Close()
{
con.Close();
con.Dispose();
}
}
Please go through this link
Getting Started with Oracle Data Provider for .NET (C# Version)
http://www.oracle.com/webfolder/technetwork/tutorials/obe/db/dotnet/GettingStartedNETVersion/GettingStartedNETVersion.htm
If you add a try/catch block in Connect(), you'll be able to catch the error.
For example:
When opening an oracle connection, connection object is null
I added the try catch block, and it returned ORA12154 - TNS could not
be resolved. After some research, I added an SID to my tnsnames.ora
file in my ODP for .NET Oracle home path, and it worked
See also Troubleshooting Oracle Net Services for troubleshooting possible connection issues from Oracle clients (such as your C# program).
But your first step is absolutely to determine the Oracle-level error (for example, ORA-12543 (could not connect to server host) or TNS-12514 (could not find service name)
MSDN: OracleException Class
public void ShowOracleException()
{
OracleConnection myConnection =
new OracleConnection("Data Source=Oracle8i;Integrated Security=yes");
try
{
myConnection.Open();
}
catch (OracleException e)
{
string errorMessage = "Code: " + e.Code + "\n" +
"Message: " + e.Message;
System.Diagnostics.EventLog log = new System.Diagnostics.EventLog();
log.Source = "My Application";
log.WriteEntry(errorMessage);
Console.WriteLine("An exception occurred. Please contact your system administrator.");
}
}
It's significant that con.ConnectionString = xyz works, but the following `con.Open()" fails. This means .Net is creating the C# object, but Oracle/TNS is failing when you try to use it.
ADDITIONAL SUGGESTIONS:
Re-read
When opening an oracle connection, connection object is null.
Read all of the suggestions, including the one about "Data Source in your connection string".
Focus on your connection string. It couldn't hurt to specify the connection string in your OracleConnection() constructor, if possible. Here's another link:
ODP.NET Connection exception
It would be great if you can verify connectivity from your PC with some other Oracle client, besides your C#/.Net program. To verify you're talking to the right TNS host and service, with the correct username/password. For example, maybe you have SQLDeveloper or sqlplus.
Finally, re-read the TNS troubleshooting link:
https://docs.oracle.com/cd/E11882_01/network.112/e41945/trouble.htm#NETAG016
What worked for me with the same error was to simply switch from the 'plain' Oracle DataAccess library, to the 'Managed' version.
This is an extemely easy change to make -
Add a Reference in your c# project to the Oracle.ManagedDataAccess library
Replace the existing use statements at the top of your Oracle client code with the following:
using Oracle.ManagedDataAccess.Client;
using Oracle.ManagedDataAccess.Types;
Include the Oracle.ManagedDataAccess.dll file with your exe
My problem is that I can't connect to my website remote MySQL server. I have read all answers in stackoverflow.com, but I can't find right answer. Here's my C# code:
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
namespace ConsoleApplication3
{
class Program
{
static void Main(string[] args)
{
SqlConnection con;
string connectionString = #"Server=[IP adress];Port=3306;Database=[database];Uid=[user];Pwd=[pass];";
con = new SqlConnection(connectionString);
try
{
con.Open();
Console.WriteLine ("Connection Open ! ");
}
catch (Exception ex)
{
Console.WriteLine("Can not open connection ! ");
Console.WriteLine(ex.Message); //shows what error actually occurs
}
Console.ReadLine();
}
}
}
Error:
A network-related or instance-specific error occurred while establishing a
connection to SQL Server. The server was not found or was not accessible.
Verify that the instance name is correct and that SQL Server is configured
to allow remote connections. (provider: Named Pipes Provider, error: 40
Could not open a connection to SQL Server)
Any ideas?
When connecting to a MySQL-Database I always used the MySQL Connector you can get here: https://dev.mysql.com/downloads/connector/net/6.9.html
You have to import the MySQL namespaces to your project and then you can use the MySQLConnection instead of the SQLConnection that is, as far as I know, only for MSSQL servers.
http://www.codeproject.com/Tips/423233/How-to-Connect-to-MySQL-Using-Csharp
try the following
string connectionString = #"Server=[IP adress]:3306;Database=[database];Uid=[user];Pwd=[pass];";
instead of
string connectionString = #"Server=[IP adress];Port=3306;Database=[database];Uid=[user];Pwd=[pass];";
i am trying to connect to an informix database in my web application and retrieve the data based on an item code entered by the user and store it in a datatable later i want to take the data from the datatable and display it on my textboxes for the item selected. its an odbc connection DRIVER={IBM INFORMIX ODBC DRIVER} in my connection string
if (DropDownList4.Text == "***.**.**.**" || DropDownList4.Text == "***.**.**.**" || DropDownList4.Text == "***.**.**.**")
{
//string abilene = ConfigurationManager.ConnectionStrings["Abeliene"].ConnectionString.ToString();
IfxConnection conn = new IfxConnection("User Id=****;Password=****;" +"Host=abkrisc1;Server=abkrisc1;" +"Service=1719;DB=circa119;");
DataTable Abilene = new DataTable();
Abilene.Columns.Add("item");
Abilene.Columns.Add("desc");
Abilene.Columns.Add("upc");
Abilene.Columns.Add("itemupc");
Abilene.Columns.Add("ctyp");
Abilene.Columns.Add("citg");
Abilene.Columns.Add("best");
Abilene.Columns.Add("disp");
Abilene.Columns.Add("mold");
Abilene.Columns.Add("csel");
IfxCommand cmd;
cmd = new IfxCommand("Select t_item,t_idsc,t_upct,t_item_upc,t_ctyp,t_citg,t_best,t_disp,t_mold,t_csel from tsckcm907 where t_item = #item'");
conn.Open();
cmd.Parameters.Add("#item", IfxType.VarChar).Value = TxtItem.Text;
try
{
IfxDataReader myreader = cmd.ExecuteReader();
Abilene.Load(myreader);
Response.Write(Abilene.Columns);
con = true;
}
catch (Exception ex)
{
throw ex;
con = false;
}
if (con == true)
{
while (Abilene.Rows.Count > 0)
{
TxtItem.Text = Abilene.Rows[0]["item"].ToString();
lbldesc.Text = Abilene.Rows[1]["desc"].ToString();
}
}
The error i get when i debugged was at conn.open() -> ERROR [HY000] [Informix .NET provider][Informix]Server abkrisc1 is not listed as a dbserver name in sqlhosts.
i have done a similar scenario with sql database, but informix i have never worked with. Please if anyone could help me with this code that would be awesome, even this code that i used was found from ibm website.
Check your informix server configuration (the problem might be in your sqlhosts file, as the error states), it should contain server with the name abkrisc1, listening at port 1719.
If that's ok, then check your DSN configuration (this may vary depending on your operating system - check out this page for details).
Documentation in internet and the error message are misleading.
I had the same error and meanwhile I found out how to solve it.
When you install the Informix Client SDK for Windows and use the ODBC driver for Informix (with or without .NET) you must pass the following parameters:
Host
Server
Service or Port
Protocol
User ID
Password
All these parameters are mandatory. The database is optional.
In your connection string the protocol is missing. In the case that any parameter is missing the OBDC driver searches the server in the registry under
32 bit driver:
HKLM\Software\Wow6432Node\Informix\SQLHOSTS\Servername
64 bit driver:
HKLM\Software\Informix\SQLHOSTS\Servername
If the server is not listed there you get the error "Server XYZ is not listed as a dbserver name in sqlhosts."
Please note that only Linux uses an sqlhosts file. On Windows the same data is stored in the registry instead.
You do NOT need to create a sqlhosts file although the error message and the documentation and several webpages make you think that.
You do NOT need to use the IBM tool SetNet32 to generate entries for your server.
You just have to pass ALL mandatory parameters to the ODBC driver and the error is gone.
It is really a pitty that IBM is not able to give a more intelligent error message.
I'm trying to connect MySQL in C# develope in Expression Blend 4
but i get following error ?
try
{
string serverConnection = "SERVER=xxx.xxx.xxx.xxx; UID=xxx; PASSWORD=xxx; DATABASE=xxx;";
MySqlConnection conn = new MySqlConnection(serverConnection);
conn.Open();
MessageBox.Show("Successfully connected");
conn.Close();
}
catch (Exception ex)
{
MessageBox.Show("Error:"+ex.Message);
}
Here is the error:
Unable to connect to any of the specified MySQL hosts
The format for connection strings is as follows,
Server=myServerAddress; Port=1234; Database=myDataBase; Uid=myUsername; Pwd=myPassword;
The most likely issue is that you are trying to remotely connect to your MySQL server in which case make sure it allows for remote connections, and then you must check and make sure the user you are trying to login as is allowed to connect from either your public IP or any public IP.
NOTE: I know this response is 2 and 1/3 years late, but I wanted this to be here for anyone else with a similar issue.
I think its more of like the placement of the parameters.
The standard format specified is this:
Server=myServerAddress; Port=1234; Database=myDataBase;
Uid=myUsername; Pwd=myPassword;
You need to change it like this:
string serverConnection = "SERVER=xxx.xxx.xxx.xxx; DATABASE=xxx; UID=xxx; PASSWORD=xxx;";
Try to change and see if that works :)
Evening all,
I'm trying to connect to a SQL Server 2012 database from C#. My connection settings when using SQL Server Management Studio are as below:-
Server Type: Database Engine
Server Name: Paul-PC\SQLEXPRESS
Authentication: Windows Authentication
Username: Greyed out
Password: Greyed out
The name of the database I'm trying to connect to is "testDB".
Here's my code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;
namespace DatabaseConnection
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void btnConnect_Click(object sender, EventArgs e)
{
SqlConnection myConnection = new SqlConnection("server=localhost;" +
"Trusted_Connection=yes;" +
"database=testDB; " +
"connection timeout=30");
try
{
myConnection.Open();
MessageBox.Show("Well done!");
}
catch(SqlException ex)
{
MessageBox.Show("You failed!" + ex.Message);
}
}
}
}
Unfortunately, my code fails to connect with the following error:-
"You failed!A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections."
Any suggestions? SQL Server is running locally.
In your connection string replace server=localhost with "server = Paul-PC\\SQLEXPRESS;"
I tested all the answers here, but for me, none worked. So I studied a bit the problem, and finally I found the connection string needed. To get this string, you do:
1. in you project name:
a. right click the project name,
b. click Add,
c. select SQL Server Database (obviously you can rename it as you wish).
Now the new desired database will be added to your project.
2. The database is visible in the Server Explorer window.
3. Left click the database name in the Server Explorer window; now check the Solution Explorer window, and you will find the "Connection String", along side with Provider, State, Type, Version.
4. Copy the connection string provided, and put it in the Page_Load method:
string source = #"Data Source=(LocalDB)\v11.0;AttachDbFilename=c:\x\x\documents\visual studio 2013\Projects\WebApplication3\WebApplication3\App_Data\Product.mdf;Integrated Security=True";
SqlConnection conn = new SqlConnection(source);
conn.Open();
//your code here;
conn.Close();
I renamed my database as Product. Also, in the "AttachDbFilename", you must replace "c:\x\x\documents\" with your path to the phisical address of the .mdf file.
It worked for me, but I must mention this method works for VS2012 and VS2013. Don't know about other versions.
Try:
SqlConnection myConnection = new SqlConnection("Database=testDB;Server=Paul-PC\\SQLEXPRESS;Integrated Security=True;connect timeout = 30");
Replacing server=localhost with server=.\SQLEXPRESS might do the job.
Note to under
connetionString =#"server=XXX;Trusted_Connection=yes;database=yourDB;";
Note: XXX = . OR .\SQLEXPRESS OR .\MSSQLSERVER OR (local)\SQLEXPRESS OR (localdb)\v11.0 &...
you can replace 'server' with 'Data Source'
too you can replace 'database' with 'Initial Catalog'
Sample:
connetionString =#"server=.\SQLEXPRESS;Trusted_Connection=yes;Initial Catalog=books;";
use this style
#"server=.\sqlexpress;"