I have been trying to connect a C# WPF app with a MySQL database. The database is on a Linux machine in my network. I have a lot of experience connecting with PHP but have never done it with a .NET product. I have read through everything I have found online. I have already downloaded and installed the MySQL connect stuff and attached it to the project. I have gone into the db and made sure it would accept queries from my work PC using phpMyAdmin. I have tried a wide variety of code to call the DB. I have changed the order of everything in connStr. I have changed the labels and formatting to try everything I have come across. I am able to connect to the DB with all of the web based tools that tie to this app so I know that I have the right info. I have never posted on here so I am sorry about the formatting. Everything I have read make this sound quite straightforward. I and am currently using this:
string connStr = "user=admin;database=test;server=192.168.0.37;password=******;"; MySqlConnection conn = new MySqlConnection(connStr);
try
{
Console.WriteLine("Trying to connect to: ..." + connStr); Console.WriteLine("Connecting to MySQL...");
conn.Open();
// Perform database operations
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
conn.Close();
Console.WriteLine("Done.");
and I am getting this error:
Test.vshost.exe Error: 0 : Unable to connect to any of the specified MySQL hosts.
A first chance exception of type 'MySql.Data.MySqlClient.MySqlException' occurred in MySql.Data.dll
MySql.Data.MySqlClient.MySqlException (0x80004005): Unable to connect to any of the specified MySQL hosts.
at MySql.Data.MySqlClient.NativeDriver.Open()...
Thank you for your help on this!
When you are trying to contact a server in a home network using a basic modem/router, it can fail to recognize or pass along the port number you sent. In this case it was not recognizing or sending 3306 (default for mysql). This would make it so it would never work without SSH tunneling. After adding SSH tunneling it worked as advertised.
Related
Backstory, I would like to build shiny apps to give to some of our data collectors so they can review what has been collected. We currently house all of our data in a cloud based MySQL server. Ideally, I would like the shiny app to pull data directly from the MySQL server so it can be fully automated without any data pulls and up 24/7.
I have been trying to first just build the connection between R and MySQL using the RMySQL package and can't seem to get it working. I have set up a specific username/password for this connection that is read only(however I have also tried my regular username which has all privileges granted). This is the code I am running;
mydb=dbConnect(
MySQL(),
user='myuser',
password='mypass',
dbname='vgtg',
host='ipaddress',
port=3306,
)
Obviously the 'ipaddress' of the server has been changed for the sake of posting here but it is a generic looking address like
'192.168.1.1'
When I run the code above I get this error message;
Error in .local(drv, ...) :
Failed to connect to database: Error: Can't connect to MySQL server on
'ipaddress' (0)
I have tried looking for previous questions posted but none seem to be exactly this error message that I am receiving. It makes me think that for some reason RMySQL is looking locally for the server when it is actually a cloud based, remote, server.
Also, is there anything more I should set up server side to allow the connection? I do have a server admin to help out but I am not sure how familiar he is with R and likewise I am not particularly familiar with working with servers. He has opened port 3306 for me and is able to see my attempts to connect through the port.
Your syntax is correct with the exception of
port=3306,
You need to drop the comma. That said, the error you received is unrelated to the syntax.
Without knowing the details of your setup, it is hard to diagnose. Where does the MySQL DB reside? For example, if it is on an AWS RDS instance, then the host isn't a standard IP address, it is something like this
mydb.cm1abc2v4mod.us-west-1.rds.amazonaws.com
Assuming that the IP address you used is correct, then the problem is most likely on the server. You need to ensure that port 3306 is open to traffic. Otherwise, R will not be able to connect to the DB.
My workbench was previously working fine until recently, but I'm now getting the following error:
I'm not sure what's relevant so I'll list out everything that I think might be relevant:
My OS is Windows and I'm using JawsDB & Heroku as my server.
I've recently tried to mess with the my.cnf file (in an attempt to enable 'LOAD DATA LOCAL INFILE')
I think this is the extent to which I've used mysql_config_editor:
I've run "SET GLOBAL local_infile = true;" after logging in to my local sql.
I've checked numbers 1-4 on the error message. Here is an image of my connection to be sure:
I think I've messed with the NetBIOS at some point, and that might be a problem as discussed here, but I don't see "manage server instances" anywhere.
I'm not sure what else might be the issue here. Thanks in advance.
Edit: After trying to connect to the MySQL server through the command line, I get "ERROR 2003 (HY000): Can't connect to MySQL server on 'lyl3nln24eqcxxot.cbetxkdyhwsb.us-east-1.rds.amazonaws.com' (10060)", which seems to be an authentication error and not a connection error according to this link. But I'm unsure how to deal with this authentication error if it is one.
I'm not sure if this constitutes as an answer, but I've managed to establish a connection through my usual wifi (as opposed to a public school's wifi). It looks like either my security settings are different when on a public wifi or the public wifi itself had some sort of security setting that was blocking my connection.
I am working with ServiceStack evaluating the ORMLite provider with MySql for use on a.NET Core 1.1 project. I am running into a curious issue I am not sure what the problem is and looking for some guidance on how to troubleshoot this further or possible fixes.
I am running the .Net Core app in a standard docker container and MySql in the standard MySql container. I have been able to successfully run MySQL and connect with the workbench tool.
What I cannot do is get the executing code of the web application to successfully connect to the MySQL container. I have tried various combinations. Those where the IP Address or hostname were wrong I received a meaningful error saying the host was unknown.
But under scenarios where server name or IP address values that are used that are appropriate for the MySQL container, I receive a generic MySQLException error. The username and password are correct. I have even used the root account to ensure that there aren't any potential security hangups.
Here is a code snippet of where I am attempting to connect. This setup was working well using a local SQL db file, there is just something I am missing with either the configuration of Docker or MySQL that I haven't been able to isolate.
const string connectionString = "Server=3400f112c973:3306;Database=ServiceDB;Uid=root;Pwd=my-secret-pw;";
container.Register<IDbConnectionFactory>(
new OrmLiteConnectionFactory(connectionString, MySqlDialect.Provider ));
using (var db = container.Resolve<IDbConnectionFactory>().Open())
{
if (db.CreateTableIfNotExists<TypeExample>())
{
//Add seed data
}
}
I have figured out my scenario.
In the MySQL Connection string, if you are using a non-standard port, you need to use the port parameter to specify the different port and omit the port entirely if using the standard port.
My issue was I was always using "Server=servername:port;" which is an incorrect format and should have been "Server=servername;Port=port;" in the cases where I was using a nonstandard port number, otherwise Port= can be omitted.
I have installed MySQL Community server on local machine and am trying to access it from .NET Core API. Something must be wrong with either the connection string or the server configurations. I have checked the server configs to make sure TCP/IP connections are allowed, checked the connection string according to tutorials but still fail to connect, getting this exception in code:
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.
Tried connecting to MSSQL database and there are no issues, so nothing else could be wrong from code-side apart from the connection string itself.
The connection string:
"SqlConnectionString": "Server=127.0.0.1;Uid=admin;Pwd=admin;Database=sys;"
SQL query in code (using Dapper):
private const string SQL_INSERT_ENTITY = #"
INSERT INTO [sys].[adminportal_restapi] (Id, FeatureName, IsEnabled, LastInsertUpdate)
VALUES (#Id, #FeatureName, #IsEnabled, #LastInsertUpdate)
";
Database layout:
Found the solution - you have to use a different connector.
Basically these changes are needed:
in project.json add this dependency: "MySql.Data.Core": "7.0.4-IR-191"
and in code change new SqlConnection to new MySqlConnection
EDIT: that package got unlisted by MySQL devs without releasing a newer version (which is a complete douchebag move, IMO), so just use this one instead: "MySqlConnector": "0.11.5" syntax for connections is identical, just it doesn't support integrated security, which might suck in some cases. Good luck
I'm using Outsystems Service Studio to develop a web application. I need to configure a connection to access a local server database. I get "Connection String test failed: Unable to connect to any of the specified MySQL hosts." I just figured out I can't connect using "localhost", because the Outsystems server is not local, but I'm not able to find a solution. what is wrong? Other details:
MySQL Server is up and running
I selected MySQL in DBMS
Inserted my schema name
Inserted the username (with all privileges granted)
Inserted the user password
Tried both basic and advanced configuration. I inserted j"dbc:mysql://127.0.0.1:3306/mydb?user=outsystems2" as connection string parameters and I get "Connection String test failed: Keyword not supported.Parameter name: mysql://127.0.0.1:3306/mydb?user". I know this connection string can't work , but I'm not able to find a functioning one. I've read many guides about this configuration, but no solution was found. Thank you all for your time and help, feel free to ask for more details
Luciano,
Is your OutSystems environment on-premises or in the cloud? Either way, you need to make sure that this server is able to reach - it as connectivity - to your MySQL database server. Using localhost or 127.0.0.1 is pretty much the same thing as this is an address for the machine where the request is running, which is, in this case, the OutSystems server. Do you have the MySQL database on your local machine? This is not a good approach as you will need to have an address that won't change otherwise the connection won't be stable and you'd have to reconfigure it all the time.
Regards