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C# MySql error: MySql.Data.MySqlClient.MySqlException [duplicate]

Trying to connect to MySQL on my web host, using Connector/Net C#/WinForms in Visual Studio 2012 Update 3, but getting the below error message:
Authentication to host '1.1.1.1' for user 'username#mydomain.com' using method 'mysql_native_password' failed with message: Access denied for user 'username#mydomain.com'#'2.2.2.2' (using password: YES)
string connectionString = "SERVER=1.1.1.1;PORT=3306;DATABASE=databaseName;UID=username#mydomain.com;PASSWORD=mypassword;";
MySqlConnection connection = new MySqlConnection(connectionString);
connection.Open();
I am connecting remotely, have whitelisted my IP (and even temporary whitelisted all (%) to test), triple checked the username and password and IP.
I originally tried the username without the domain ( username rather than username#mydomain.com) but it gave me the below error:
Authentication with old password no longer supported, use 4.1 style passwords.
Any assistance would be much appreciated, thanks!

Its problem of 'Remote Database Access Hosts'.
"You can allow external web servers to access your MySQL databases by adding their domain name to the list of hosts that are able to access databases on your web site."
MySql access is not granted to IP address of the system at which application is running.(in your case its '2.2.2.2' ).
Note:- '2.2.2.2' is your public IP address.

Two possible things:
MySQL is case sensitive make sure that the case of Database= in your connection string matches with the actual database name
You may have to grant privileges to the user.
I hope this help you.

Check your application settings file (or wherever you have stored the connection string).
In my case the application was using the old connection string (which was not valid). I was assuming that the change I made in the code of the settings file is reflected to the designer (of the settings file). But it was not!

After creating a new user in MySQL, in MySQL Workbench "Test Connection" will succeed but the C# MySqlConnection.Open() will throw the same exception and message as the question (tested with localhost and 127.0.0.1 and the local ip address).
The reason is that MySqlConnection.Open() will somehow use SELECT privilege, and you need to at least enable the SELECT privilege for the new user. The error message is misleading.

This might be related to the case of specific Membership SQL Server based instructions on ASP.NET 4.5, workaround is to create new membership in web.config, drop mvc 4 AccountControler and use old from MVC3 more here or in the internet:
http://www.nsilverbullet.net/2012/11/06/using-mysql5-as-membership-backend-for-aspnet45-mvc4-application/

In my case updated password was not used. I just generated the password using Password Generator and copy it but forgot to click Change Password.
Also check the user is added to the database and has Privileges.

For me, using the actual IP address instead of the domain name solved the problem

While Whitelisting my Ip on cpanel i had accidentally put a space in there after my ip address.[Should have been handled by them]
I added the ip again and it worked.

In my case, the problem was misleading as well.
Had quite a few windows terminals running "the same" .net app all connecting to a remote MySQL server (installed in a windows server machine). However, only one always popping the specific error when anyone clicked to run the .net application. ODBC test connection passed successfully, and no matter if the error popped, when presing OK the application continued loading successfully finally and then worked fine.But again afterwards , when anyone tried to run in for the first time the message appeared. and I repeat only in this specific terminal! The fix finally came when I noticed, that it was only in this specific terminal with the problem that we had forgotten DHCP enabled! and "although it was given always the same IP" from our IT policies, however it only worked when we disabled DHCP and set this IP, SUBNET and GW, as fixed !

Check with a program like Navicat that the mysql server user has a native password. Everything is correct but if you are getting this error check the version of the link DLL
This error; Mysql.Data.dll and Mysql Server version mismatch error. Download and install an older version
https://downloads.mysql.com/archives/c-net/
Mysql Version < 4.5
Mysql.Data.Dll version= 6.0.3

How to connect to a SQL Server instance without knowing the Initial Catalog?

I'm writing a portable program that can be used on other computers as well as mine and It also connects to the SQL Database on that computer.
So the problem is that I don't have the database name of that computer. How can my program connect to that Database without previously knowing the database name?
In other words, I don't have enough information to create a complete ConnectionString.

Connect to SQL Server's master database first.
Then, using this query, you can get data from databases in your database:
SELECT name FROM master.dbo.sysdatabases
Using the site below, you can find the right Connection strings for you :
https://www.connectionstrings.com/

You can use a dot in the connection string to represent.tbe local server.
Create a txt file, rename the extension to UDL. Open the UDL file and put a dot, a full stop:
If you have installed a SQL Instance (ie not the default instance) it will be .\InstanceName
Choose the Database drop down and click Test Connect.
Finally close the URL file and open it with NotePad and you will see the connection string.

ODBC ISAM_EOF without any reason

I have a strange behavior with an ODBC Driver and the underlying COBOL database. The database driver is acuODBC of AcuCorp(now Microfocus), the database itself is a COBOL database.
The DSN is a system DSN and works just fine. Via Access/Excel u can read/write data with the DSN successfully.
In C# the ODBCConnection.ConnectionState is open. Retreiving the table headers works just fine. But when reading data, a strange error occurs. Here is a summerize of the trace log:
[Retreiving Column Headers]
ISAMRestrict - NO_ISAM_ERR
ISAMRewind - NO_ISAM_ERR
ISAMNextRecord – ISAM_EOF
This occurs when I add a WHERE clausel to the SELECT statement. When I do not add a WHERE clausel and just retreive the whole table, it takes incredible long (about 12 minutes for 40000 records), but at least I retreive data.
So my question would now be, has anyone else occured such a strange behavior with an ODBC driver? End of File where data should be?
Just as a side note, I have contacted Microfocus too, if they have a solution I will post it here.

It seems to be Windows UAC reliant. As our application run in compatibility mode, UAC visualization is active and causing may some problems. The reason for this is, that the COBOL databse is a file based database, and the client where are coding for uses these files in ODBC DSN config directly instead of running an ODBC server to handle the requests.
So the UAC leads to some strange behavior.

Access denied for user 'root'#'localhost' (using password: YES) in Visual Studio

Kindly bear with me. I am a Microsoft SQL Server person with loads of Visual Studio experience, but I need to get something done using a MySQL database.
I am trying to create a little tool here that will allow our developers to quickly update database records, and I am using Visual Studio to create a small Windows Form to do this.
In a Microsoft SQL Server connection string, I could write something like this:
Server=myServerAddress;Database=myDataBase;User Id=username;Password=password;
In a MySQL connection string, there appear to be multiple other options, but the first one looks basically the same:
Server=myServerAddress;Database=myDataBase;Uid=username;Pwd=password;
When I attempt to open the MySQL connection from my PC, I get the exception listed in the title (actually, it shows the Uid value and the IP Address of my PC instead of localhost, but I am hoping more people will recognize the error easier this way):
public static void MySQLi_Connect() {
m_err = null;
var str = Properties.Settings.Default.ConnStr;
try {
m_conn = new MySqlConnection(Properties.Settings.Default.ConnStr);
m_conn.Open();
} catch (MySqlException err) {
ErrorLog("MySQLi_Connect", err);
}
}
I did a search, and it seems that the Uid on MySQL needs to be granted access from the specific IP Address that the connection is being made from.
Further, I found this on the mysql.com doc pages:
If you do not know the IP address or host name of the machine from which you are connecting, you should put a row with '%' as the Host column value in the user table. After trying to connect from the client machine, use a SELECT USER() query to see how you really did connect. Then change the '%' in the user table row to the actual host name that shows up in the log. Otherwise, your system is left insecure because it permits connections from any host for the given user name.
A few things:
It looks like I can connect to MySQL by using a % setting in the Uid jp2code, but MySQL says I need to change that back right away to remove system vulnerability.
Microsoft SQL Server did not seem to require this - or, if it did, I simply never was slapped in the face with this vulnerability issue like MySQL is doing.
Now, I ask:
If this is going to be a tool used by different developers on different PCs, is it common practice to turn the blind eye to this horrendous system vulnerability?
Is this not really as big of a concern as MySQL is making it appear?
What is the best way to continue with a Windows Forms application that needs to connect from various locations? Obviously, I do not want to continuously be adding more entries for a particular application every time another developer wants to use the tool or someone tries to run it from a different PC.

You can configure the security of your MySQL server as strong as you like, usually you dont connect users but applications. So if you have your root user without password in production environment is your fault. Usually developers have access to development environment, so this is not a big deal.
Of course try to have as many users as roles you need, for your example I think one user is enough. In production use a secure config file for save a secure password and set you mysqlserver restricted.

I was having the same issue and I found out that the password wasn't correct.
GO to your sql command line and type the code below:
mydb in the line below is the name of the database you are working on.
passwd in the line has to match the password you have in c# code so in your case "password"
grant all privileges on mydb.* to myuser#localhost identified by 'passwd';

Like OP says you can wildcard the hostname portion. I used this on our dev-server (not recommended for production servers):
update mysql.user set host = '%' where host='localhost';
Then I had to restart the server to make MySQL use it (propably I could just have restarted the MySQL service).

Cheat application to connect to different SQL Server database

At work I wrote an application that processes data from a SQL Server database and outputs it in file format.
Now I need to use it at home and since app has hard-coded connection string I've got a problem. I got a copy of database at my company, the original database is inaccesable from the outside of the company.
Connection string format looks like this
Data Source=serverName-01;Initial Catalog=dbName_01;Integrated Security=True;Pooling=False
I've tried to cheat app by editing windows hosts file:
serverName-01 127.0.0.1
But it did not work. Is there a way to make it work without going to work and editing source code ?
Lesson learned hard way - never hard-code connection srings :<

To do this you can use an alias defined in SQL Server Configuration manager. Create an alias for your local instance that has the exact same name as the one in the connection string.
Have a look at the following article for how to do this (it's pretty simple):
Create or Delete a Server Alias for Use by a Client (SQL Server Configuration Manager)