I'm trying to use dapper with mysql in .net core 1.0. I'm using this mysql connector: https://github.com/bgrainger/MySqlConnector
I know the connector is in alpha but I was wondering if anyone had a similar issue when using it together with dapper.
This is my simple model:
public List<GeneralModel> GetAllLists()
{
try
{
using (DbConnection connection = new MySqlConnection("Server=localhost;Database=lists;Uid=Unnamed;Pwd=lol;"))
{
return connection.Query<GeneralModel>("SELECT * FROM lists.general").ToList();
}
}
catch (Exception)
{
throw;
}
}
And this is the controller:
public IActionResult Index()
{
GeneralModel GenRepo = new GeneralModel();
return View(GenRepo.GetAllLists());
}
When I go to the index page for the first time, it works. If I refresh, I get an "Access denied for user...". I have no idea what could be causing the error. I don't think the problem is in my code.
Edit:
I guess the problem is in the connector, since this also returns the error after a refresh:
List<GeneralModel> lists = new List<GeneralModel>();
using (DbConnection connection = new MySqlConnection("Server=localhost;Database=lists;Uid=Unnamed;Pwd=lol;"))
{
using (DbCommand myCommand = connection.CreateCommand())
{
myCommand.CommandText = "SELECT * FROM lists.general";
connection.Open();
using (DbDataReader myReader = myCommand.ExecuteReader())
{
while (myReader.Read())
{
GeneralModel tmpGen = new GeneralModel();
tmpGen.name = myReader["name"].ToString();
tmpGen.description = myReader["description"].ToString();
tmpGen.language = myReader["language "].ToString();
lists.Add(tmpGen);
}
}
connection.Close();
}
}
return lists;
This bug was caused by MySqlConnector not correctly handling the fast path for a COM_CHANGE_USER packet.
MySQL Server (versions 5.6 and 5.7) doesn't appear to immediately accept the user's credentials, but always returns an Authentication Method Switch Request Packet. MariaDB (which you are using) does implement the fast path and immediately returns an OK packet.
The connector has now been updated to handle this response and should stop throwing the spurious "Access Denied" exceptions. The fix is in 0.1.0-alpha09.
Related
I am trying to print crystal report in PDF format , and on my local machine it’s working fine. But when I publish application to the server, it’s giving me the following error on Print button.
Exception Details: System.Runtime.InteropServices.COMException: Database logon failed.
Below is my code in my controller
public ActionResult Export(int Id)
{
ReportDocument rd = new ReportDocument();
rd.Load(Path.Combine(Server.MapPath("~/Reports/GcReport.rpt")));
var query = rLAService.GetGeneralConsignmentById(Id);
var querylist = new List<GeneralConsignmentDto> { query };
rd.SetDataSource(querylist);
rd.SetParameterValue("Id", Id);
//rd.SetDataSource(rLAService.GetGeneralConsignmentById(Id));
Response.Buffer = false;
Response.ClearContent();
Response.ClearHeaders();
Stream stream = rd.ExportToStream(CrystalDecisions.Shared.ExportFormatType.PortableDocFormat);
stream.Seek(0, SeekOrigin.Begin);
return File(stream, "application/pdf", "GC Report.pdf");
}
Edit
Ok, after digging throuh the problem, i found that error is table name generalconsignment1 does not found. But problem is it is taking automatically instead of generalconsignment.now how to handle this situation?
I'm creating a back-end server application in Dart which is using a MySQL database to store data. To make the SQL call I'm using the ConnectionPool from SqlJocky.
What I do when the app starts:
Create a singleton which store the ConnectionPool
Execute multiple queries with prepareExecute and query
Locally this approach is working fine. Now I pushed a development version to Heroku and I'm getting connection issues after a few minutes.
So I wonder, do I need to close/release a single connection from the pool I use to execute a query? Or is the connection after the query placed again in the pool and free for use?
The abstract base class for all the MySQL stores:
abstract class MySQLStore {
MySQLStore(ConnectionPool connectionPool) {
this._connectionPool = connectionPool;
}
ConnectionPool get connectionPool => this._connectionPool;
ConnectionPool _connectionPool;
}
A concrete implementation for the method getAll:
Future<List<T>> getAll() async {
Completer completer = new Completer();
connectionPool.query("SELECT id, name, description FROM role").then((result) {
return result.toList();
}).then((rows) {
completer.complete(this._processRows(rows));
}).catchError((error) {
// TODO: Better error handling.
print(error);
completer.complete(null);
});
return completer.future;
}
The error I get:
SocketException: OS Error: Connection timed out, errno = 110, address = ...
This doesn't fully answer your question but I think you could simplify your code like:
Future<List<T>> getAll() async {
try {
var result = await connectionPool.query(
"SELECT id, name, description FROM role");
return this._processRows(await result.toList());
} catch(error) {
// TODO: Better error handling.
print(error);
return null;
}
}
I'm sure here is no need to close a connection with query. I don't know about prepareExecute though.
According to a comment in the SqlJocky code it can take quite some time for a connection to be released by the database server.
Maybe you need to increase the connection pool size (default 5) so you don't run out of connections while ConnectionPool is waiting for connections to be released.
After some feedback from Heroku I managed to resolve this problem by implementing a timer task that does every 50 seconds a basic MySQL call.
The response from Heroku:
Heroku's networking enforces an idle timeout of 60-90 seconds to prevent runaway processes. If you're using persistent connections in your application, make sure that you're sending a keep-alive at, say, 55 seconds to prevent your open connection from being dropped by the server.
The work around code:
const duration = const Duration(seconds: 50);
new Timer.periodic(duration, (Timer t) {
// Do a simple MySQL call with on the connection pool.
this.connectionPool.execute('SELECT id from role');
print('*** Keep alive triggered for MySQL heroku ***');
});
All work fine if I use custom main ( void main() instead of shared static this() ).
With default main I am getting "Access Violation" error. It's look like MySQL not allow connecting to it from localhost, but in my.ini I added string:
bind-address = 127.0.0.1
code, if it's help:
import std.stdio;
import std.path;
import std.file;
import std.string;
import dini;
import vibe.d;
import colorize;
import ddbc.all;
shared static this()
{
auto settings = new HTTPServerSettings;
settings.port = 8080;
settings.bindAddresses = ["::1", "127.0.0.1"];
listenHTTP(settings, &hello);
auto parseconfig = new ParseConfig();
auto db = new DBConnect(parseconfig);
}
void hello(HTTPServerRequest req, HTTPServerResponse res)
{
res.writeBody("Hello, World!");
}
class ParseConfig
{
string dbname;
string dbuser;
string dbpass;
string dbhost;
string dbport;
this()
{
try
{
//getcwd do not return correct path if run from task shoulder
string confpath = buildPath((thisExePath[0..((thisExePath.lastIndexOf("\\"))+1)]), "config.ini");
//writefln(thisExePath[0..((thisExePath.lastIndexOf("\\"))+1)]); // get path without extention +1 is for getting last slash
//string confpath = buildPath(thisExePath, "config.ini");
if (!exists(confpath))
{
writeln("ERROR: config.ini do not exists");
}
auto config = Ini.Parse(confpath);
try
{
this.dbname = config.getKey("dbname");
this.dbuser = config.getKey("dbuser");
this.dbpass = config.getKey("dbpass");
this.dbhost = config.getKey("dbhost");
this.dbport = config.getKey("dbport");
}
catch (Exception msg)
{
cwritefln("ERROR: Can't parse config: %s".color(fg.red), msg.msg);
}
}
catch(Exception msg)
{
cwriteln(msg.msg.color(fg.red));
core.thread.Thread.sleep( dur!("msecs")(1000));
}
}
}
class DBConnect
{
Statement stmt;
ParseConfig parseconfig;
this(ParseConfig parseconfig)
{
try
{
this.parseconfig = parseconfig;
MySQLDriver driver = new MySQLDriver();
string url = MySQLDriver.generateUrl(parseconfig.dbhost, to!short(parseconfig.dbport), parseconfig.dbname);
string[string] params = MySQLDriver.setUserAndPassword(parseconfig.dbuser, parseconfig.dbpass);
DataSource ds = new ConnectionPoolDataSourceImpl(driver, url, params);
auto conn = ds.getConnection();
scope(exit) conn.close();
stmt = conn.createStatement();
writefln("\n[Database connection OK]");
}
catch (Exception ex)
{
writefln(ex.msg);
writeln("Could not connect to DB. Please check settings");
}
}
}
Also I run next command:
GRANT ALL PRIVILEGES ON *.* TO 'root'#'%' IDENTIFIED BY 'password' WITH GRANT OPTION;
FLUSH PRIVILEGES;
also I tried different bind-address like: 0.0.0.0 and localhost but without result. After every new binding I did restart of MySQL service.
I am using this driver http://code.dlang.org/packages/ddbc
What's wrong?
To continue on my comment ( Can't connect to MySQL/MariaDB database from vibed app ).
I just tested, and it's definitely the event loop ;)
Instead of:
auto parseconfig = new ParseConfig();
auto db = new DBConnect(parseconfig);
Just do:
runTask({
auto parseconfig = new ParseConfig();
auto db = new DBConnect(parseconfig);
});
Worked for me (DMD 2.067.0 / Vibe 0.7.23 / ddbc 0.2.24 / colorize & dini master).
To answer your comment ( Can't connect to MySQL/MariaDB database from vibed app) : the event loop starts inside the main function.
What happens when you launch a D application ? The entry point is a C main inside the runtime, which initialize it (the runtime), including module constructor, run the unittest (if you've compiled with -unittest), then call your main (which name is "_Dmain" - useful to know if you want to set a breakpoint with GDB).
When Vibe.d's main is called, it parses command line argument, an optional config file, and finally, starts the event loop. Any code that wish to run once the event loop has started should use runTask and similar, or createTimer. They should not call the code directly from the static constructor (it's actually one of the most common mistake when starting with Vibe.d).
I ran into an issue that could be related while developing mysql-lited, an alternative MySQL/MariaDB driver.
The issue I think is related to a module initialization order bug in phobos/SHA1, which I believe is still open in 2.067.1. The suggested work-around is to use VibeCustomMain instead, and define your own main(). You can just copy the defaul main() from appmain.d and use that.
Alternatively you could try mysql-lited and see if that works better for you.
I am fighting with stored procedure with referenced linkedserver. Linked server is accesible over internet via port forwarding - so no VPN, LAN.
Servers are on both sides MS SQL SERVER 2008 EE v. 10.0.5512
Configurations Linked server, DTC:
cannot insert images yet:(
enable promotion of distributed transaction = false
RPC = false
RPC out = false
Network DTC Access checked
Allow inbound true
Allow outbound true
No authentication Required
Stored procedure looks like
CREATE PROCEDURE [dbo].[spSynchronizeArticles]
-- Add the parameters for the stored procedure here
(
#pDebug bit,
#siteId bigint
)
AS
BEGIN
SELECT *
FROM [LinkedServer].[MyDatabase].dbo.Storages
WHERE Storage.siteId = #siteId
RETURN 0
END
As you can see no transaction here. If I am correct the MS DTC is creating transaction every time when the linked server is called.
I am calling this procedure from c# like this
SqlCommand sqlCmd = new SqlCommand("spSynchronizeArticles");
sqlCmd.CommandType = CommandType.StoredProcedure;
sqlCmd.Parameters.AddWithValue("#pDebug", false);
sqlCmd.Parameters.AddWithValue("#siteId", siteId);
SqlParameter returnValue = new SqlParameter("returnVal", SqlDbType.Int);
returnValue.Direction = ParameterDirection.ReturnValue;
sqlCmd.Parameters.Add(returnValue);
using (SqlConnection conn = new SqlConnection(Context.LocalData.ConnectionString))
{
try
{
try
{
conn.Open();
sqlCmd.Connection = conn;
sqlCmd.ExecuteScalar();
return Convert.ToInt32(returnValue.Value);
}
catch (Exception ex)
{
//log exception to file
return -1;
}
}
finally
{
conn.Close();
}
}
}
This c# code is called in infinite while to synchronize data. In same Thread and while there is also another method called which is getting data from file (if any exist) and saving them to local DB.
The SynchronizeArticles method is invoking more often and everything is working, but once the method for getting data from file is called, the SynchronizeArticles always throw this exception
System.Data.SqlClient.SqlException (0x80131904): MSDTC on server
'LocalServer\SQLEXPRESS2008' is unavailable.
The method is using Transaction and looks like
public void FillDataFromViewWithTrans(DataTable dt, string wherePhrase)
{
dt.Rows.Clear();
SqlCommand sql = new SqlCommand(String.Format(#"SELECT *
FROM SomeView
{0}", String.IsNullOrEmpty(wherePhrase) ? String.Empty : "WHERE " + wherePhrase));
using (SqlConnection conn = new SqlConnection(Context.LocalData.ConnectionString))
{
SqlTransaction trans = null;
try
{
try
{
conn.Open();
trans = conn.BeginTransaction(IsolationLevel.RepeatableRead);
sql.Transaction = trans;
sql.Connection = conn;
SqlDataAdapter dA = new SqlDataAdapter(sql);
dA.Fill(dt);
trans.Commit();
}
catch (Exception ex)
{
trans.Rollback();
//log exception to file
return;
}
}
finally
{
conn.Close();
}
}
}
This is just illustration samples :)
Tell me what I am missing.
Additionally I have big troubles with the MS DTC with various errors
From C# code when some users calls the procedure manually they sometimes got exception:
The operation could not be performed because the OLE DB provider
'SQLOLEDB' was unable to begin a distributed transaction.
When I put the begin distributed transaction inside the stored procedure I got:
Warning: Fatal error 8510 occurred at Apr 10 2013 9:07AM. Note the
error and time, and contact your system administrator.
What only helps is the restart of the windows service or the UI application. From the MS SQL management studio the procedure works all the time without problems.
Now I must say I am desperate, what am I missing?
Edit:
int i = 0;
while (true)
{
i++;
if ((i % 9) == 0)
{
//local select with transaction Works all the time
CallLocalSelectWithTransaction();
}
// CallProcedure works 8 times, after first calling of CallLocalSelectWithTransaction
// the callProcedure works no more.
CallProcedure(); // procedure with linked server
}
I am writing a bulk email program using the JavaMail api. I have a Microsoft Exhange server which I am trying to send the emails in to. When I run my program I get the following error:
**com.sun.mail.smtp.SMTPTransport.issueSendCommand(SMTPTransport.java:2057)
at com.sun.mail.smtp.SMTPTransport.finishData(SMTPTransport.java:1862)
at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:1100)
at javax.mail.Transport.send0(Transport.java:195)
at javax.mail.Transport.send(Transport.java:124)
at SendEmail.postMail(SendEmail.java:100)
at EmailGenerator.main(EmailGenerator.java:52)**
The part of my code trying to send the message is as follows:
Properties props = new Properties();
props.put("mail.smtp.host", email_server);
props.put("mail.transport.protocol", "smtp");
props.put("mail.smtp.auth", true);
class EmailAuthenticator extends Authenticator {
String user;
String pw;
EmailAuthenticator (String FROM, String PASSWORD)
{
super();
this.user = FROM;
this.pw = PASSWORD;
}
public PasswordAuthentication getPasswordAuthentication()
{
return new PasswordAuthentication(user, pw);
}
}
Session session = Session.getInstance(props, new EmailAuthenticator(USER, PASSWORD));
session.setDebug(debug);
System.out.println("Session created");
.. CREATED MESSAGE HERE...
Transport transport = session.getTransport("smtp");
transport.connect(exchange_server,user,password);
transport.send(msg);
transport.close();
I wonder am I missing some configuration on the Exchange server side, or is an issue with my code?
OK I figured out where I was going wrong here and am posting up the answer incase anybody else can get some value out of it. I had the following line of code:
props.put("mail.smtp.auth", true);
This was telling my application that it needed to authenticate to the SMTP server, when in fact it didnt. This was causing my application from logging into the SMTP server and sending the email and thus producing the error message. Setting this property to false or not having this line of code fixed the issue for me. This line of code is only necessary for SMTP servers that require you to login, which my Exchange server didnt.