c# - NullReferenceException in MySqlClient.NativeDriver -

-

i have long running program exectues mysql-queries every 5 minutes (timed thread). after has run approximately 10 hours nullreferenceexception thrown following stacktrace:

at mysql.data.mysqlclient.nativedriver.getresult(int32& affectedrow, int32& insertedid)    bei mysql.data.mysqlclient.driver.getresult(int32 statementid, int32& affectedrows, int32& insertedid)    @ mysql.data.mysqlclient.driver.nextresult(int32 statementid)    @ mysql.data.mysqlclient.mysqldatareader.nextresult()    @ mysql.data.mysqlclient.mysqldatareader.close()    @ mysql.data.mysqlclient.mysqlcommand.resetreader()    @ mysql.data.mysqlclient.mysqlcommand.executereader(commandbehavior behavior)    @ mysql.data.mysqlclient.mysqlcommand.executenonquery()    @ myownprogram.mysql.senddata(string sqlcommmand)

the senddata method following (lockdb of type object)

public void senddata(string sqlcommmand) {             try {                 using(mysqlcommand command = connection.createcommand()) {                     command.commandtimeout = 5;                     command.commandtext = sqlcommmand;                     lock(lockdb) {                         command.executenonquery();                     }                 }             } catch(mysqlexception e) {                 throw e;             } catch(exception e) {                 // logging             }         }

the connection opened when calling constructor of mysql-class , disposed when calling destructor or calling dispose(). can tell me did wrong?

i recommend leaving connection handling ado.net:

public void senddata(string sqlcommmand)  {     using (var con = new mysqlconnection(connectionstring))     using(var cmd = con.createcommand())      {         con.open();         cmd.commandtimeout = 5;         cmd.commandtext = sqlcommmand;         cmd.executenonquery();     } }

you no longer need finally statement. add try/catch if need log make sure propagate exception , not consume it.


Comments

Post a Comment

Popular posts from this blog

ASP.NET/SQL find the element ID and update database -

-
basically i've got update query runs when click submit button. i have asp:repeater in page layer inside this <asp:repeater id="dgbookings" runat="server" onitemdatabound="itemdb"> <itemtemplate> <div class="bookingscontent"> <div class="bookingdetails" id="<%# databinder.eval(container.dataitem, "booking_ref") %>"> <p class="infotext"><%# databinder.eval(container.dataitem, "adults") %> <asp:linkbutton onclick="editdetails" text="edit..." runat="server"></asp:linkbutton></p> <p class="infotext"><asp:linkbutton onclick="submitdetails" text="submit..." runat="server"></asp:linkbutton></p> </div> </div> </itemtemplate> <asp:repeater> and outputs ...
Read more

jquery - appear modal windows bottom -

-
i have modal windows in application, work fine <div id="modal" class="modal hide fade" tabindex="-1" role="dialog" aria-labelledby="mymodallabel" aria-hidden="true"> but when modal appears, appear top of windows, , want appear bottom the application joomla 3.0! , using template of meet gavern any idea? i found solution i modified de css in bootstrap .modal.fade { top:-25%; -webkit-transition:opacity .3s linear, bottom .3s ease-out; -moz-transition:opacity .3s linear, bottom .3s ease-out; -ms-transition:opacity .3s linear, bottom .3s ease-out; -o-transition:opacity .3s linear, bottom .3s ease-out; transition:opacity .3s linear, bottom .3s ease-out; }
Read more

c++ - Compiling static TagLib 1.6.3 libraries for Windows -

-
i having super hard time compiling , using taglib 1.6.3 in qt project. i've tried can think of. taglib claims supported through cmake i'm not having luck. furthermore, i'm confused kinds of files need qt libs! i've built *.a files, *.lib, , *.dll. understand far... believe since i'm working in windows *.lib want. no matter do, end "undefined references" taglib functions try use when try compile qt project. have tried mingw32, msys, visual studio 2008, , cross-compiling windows on linux. turning nothing. what makes less sense me if compile same taglib source qt on mac (g++ think?) works fine! somewhere in windows compilation procedures have going wrong. have been smacking face on desk 30 (on , off) hours trying figure out. since qt uses mingw must compile taglib same compiler? if compile *.lib's visual studio not compatible? are *.a libraries usable in windows? (assuming mingw) i'm still trying handle on c++ stuff, after reading coun...
Read more