I'm working on Win10 64bit with Qt5.10.1, VS2017, MySql 8.0(64it). Everything is fine in my computer. After I deploy my application on other computers, a error message "Driver not load" pop up.
I have checked many forums including two posts in stackoverflow, [Qt][QMYSQL] Deployed app - Driver not loaded
Deploying qt mysql application
But it doesn't work for me. The following are the dll files in my folder:
qsqlmysql.dll is included in the folder sqldrivers.
All of the platform, software, SDK are 64 bit. can anyone help me? thanks.
Thanks everyone who answer my question. I tried many methods and almost give up. I never used MySQL before and this time I choose the newest MySql 8.0.12. I ignore the procedure and post the solution directly:
Beside libmysql.dll and qsqlmysql.dll, other two *.dll files are also necessary (but no solution I searched refers to them): libeay32.dll and ssleay32.dll, they are located at MySql/bin/. For my computer, they are contained in the system path, while for other computers that do not install MySql, they lack these two. Thus, we need to copy them to the package as well.
For anyone who encounter the same problem, for example using the newest MySql 8.0, you can try this method.
Related
Before anyone marks this a duplicate, please read to the end, as none of the many similar questions helped.
I've just installed Delphi Community Edition and MySql (recommended download from this link) on Windows 11, but am having trouble connecting Delphi to MySql.
I used MySql Workbench to create a new connection, and created a new database with a table and some sample data.
If I start Delphi and create a new Windows VCL project, then choose Tools -> FireDAC Explorer, then try to expand the connection, I get an error "Cannot load vendor library [libmysql.dll, libmariadb or libmysqld.sll]"
I'm assuming that only libmysql.dll is relevant to me, as I don't use Maria, and don't have the other DLL anywhere on my system. I used sigcheck to check that I indeed have a 64-bit version of the DLL.
I have the same error if I use the Data Explorer in Delphi itself.
I read a lot of questions here about this exact error, but all of the ones I've seen suggest one of two things, neither of which apply here...
Add the DLL's location to the PATH environment variable - I have libmysql.dll in the C:\Program Files\MySQL\MySQL Server 8.0\lib folder, and have added that to my PATH environment variable, but it didn't help. I restarted Delphi, but no joy. I even added a TEdit to my form in Delphi, with the following code...
Edit1.Text := GetEnvironmentVariable('PATH');
This confirmed that I had set the environment variable correctly.
Copy the DLL to the project's bin folder. I tried this as well, and it didn't make any difference. However, as I haven't got as far as trying to connect my code to MySql, I didn't expect this to help. I can't even get Delphi itself to connect.
Anyone any ideas? I know there are a lot of questions about this error, but none of them worked for me.
Thanks
Please check the rest of the error message. Sometimes it specifies the bitness of the DLL you need. It's easy to miss that bit and get the wrong version.
I think MySql comes with a 64-bit DLL, but for some reason I never worked out, Delphi seems to need a 32-bit version. I had to search around and download one from a 3rd-party site, which I don't like, but it did work.
NOTE: I've been successfully building these DLLs that can be executed by LabView for over 15 years now (and Excel too, recently). As a matter of fact, LabView can view all the entry points into the DLL, it just can't execute them.
Having taken out MySQL and Oracle/OCI functionality, LabView can now execute my code properly. It appears the culprits are in, libmysql.lib and oci.lib
I guess the easy way to replace the MySQL library is with MariaDB. Any suggestions for OCI?
Turns out the linking and build were fine. With the instantclient installation Oracle doesn't make any changes to the registry so that the OS can find OCI.DLL. When I used LabView to load OCI.DLL from the instantclient directory, those functions loaded fine, so I then placed OCI.DLL in the same directory as my LabView source and everything worked as it should.
The MySQL issue was resolved with linking to mysqlclient.lib instead of libmysql.lib
I think it's important to note that Oracle provided no help or support.
I built a qt application that connects and queries a database using mysql . it works perfectly fine on my development computer (the computer with Qt Creator on it). but when I deploy it using windeployqt.exe and run it on another computer it doesn't connect to the database for some odd reason.
Note that I do have a working database (mysql as well) on the other computer (the one that fails to connect to the database)
I'm not sure what to do, I tried using addLibraryPaths but it didn't work (I'm not even sure if I did it correctly).
I'm using :
mysql server 5.5.36
workbench 6.0
Qt Creator 5.4.0
I also tried looking into statically building my application but I failed to understand the procedures in doing so.
I would greatly appreciate it if any of you Qt gods could help with this.
i finally found the problem and solved it.
problem: for some reason the target computer wasnt recognizing or reading libmysql.dll in C:\Windows ,and thanks to #Marco i used db.LastError and got my application to display the error , it was "Driver not Loaded Driver not Loaded" which meant that there was something wrong with libmysql.dll (note i copied this dll from MySql folder installed on the target machine )
Solution : i had to copy libmysql.dll from my development machine and place it in C:\Windows on the target machine (i noticed that libmysql.dll on my target machine was smaller in size than the one i used on my development machine)
for some reason the program only operates when the libmysql.dll from the development machine is present in C:\Windows in the target machine
this solution should fix any "Driver not loaded" or "QMySQL driver not loaded "(etc) errors . thanks everyone for trying to help , thanks again #Macro
I assume you built your application in release mode instead of debug mode.
If you have libmysql.dll and qsqlmysql.dll alongside your executable. Create a directory/folder and name it sqldrivers. Place qsqlmysql.dll in the directory you created and deploy it alongside your executable.
PS: I didn't see nnb's comment earlier. I think he's saying the same thing as my answer
From the comment we have cleared that there is a problem loading the driver, I am confident that you have the put qsqlmysql.dll in the correct place, as you have used the deploying utility, so I suspect that the problem is qsqlmysql.dll needs another dll that cannot be found in the system path.
I suggest that you run this tool:
http://www.dependencywalker.com/ on the qsqlmysql.dll
That will help you finding out what is missing, when you find that out, you will probably have to modify the system path or to install a dll that is missing.
I know this thread is old, but I've been having the same issue, and the solution was very easy (once you know).
The problem is that when you execute your application inside Qt, it will find the needed dll to load the drivers (libmysql.dll) if you located it in the correct Qt folder (Qt/path_to_compiler/bin), in my case: C:\Qt\5.9.1\msvc2017_64\bin. But when you try to execute the deployed executable, it is not able to find it. You will notice that the problem is solved if you paste the dll in C:\Windows, as #Nelioussness said. But that's not the solution, as it won't work in a different computer.
Just go to MySQL installation folder and look for the file libmysql.dll if you didn't do it before. In my case, it was located in C:\Program Files\MySQL\MySQL Server 5.7\lib. Once you find it, copy it to your release folder, exactly at the same level as the executable. It didn't work for me when I put it inside 'sqldriver' folder and everything was solved by just putting it outside, next to the .exe
Hope this helps :)
I got a community server version of MySQL5.6 for windows7 32 bit.
and also downloaded windows installer for the same windows version.
Everything was prepared correctly.
I saw on a blog giving me a step-by-step manual for installing MySQL 5.6 on winodws7 32bit.
I did the instruction accordingly and it always stops processing in the phrase of starting service. I completely don't know what the problem is.
I googled it for like three hours and got nothing relevant to this problem.
It never processes any further without any kind of alerts, no matter how much I wait.
Please help me out.
My OS
Windows7 Ultimate K 32bit, Service Pack1
TURN OFF WINDOWS FIREWALL COMPLETELY BEFORE INSTALLING
This was one of the only threads I could find on this issue and the current answers did not cut the mustard for me.
MySQL 5.6.21, both x86 and x64, did not want to get past "Starting Server" and would give me the "MySQL install taking longer than expected" message.
I tried all of the registry cleaner, folder deletions, etc to no avail.
I am running Windows 7 x64 and I finally decided to check the event viewer to find this:
0x80070422 turns out to be some unspecified firewall error and boom, it struck me like lightning.
I hope this post helps future visitors!
Have you installed other version of MySQL before？ I have experienced this case ,but I installed MySQL5.5 and uninstalled it. I solved it by clearing regedit and deleting the folder of MySQL in the directory（C:\ProgramData.This directory is hidden by default in Windows.）,then reinstalled it.
Follow this link http://tadeparti.com/pages/?page_id=808.
And do remember to delete everything under the C:\program files\mysql folder, including the odbc stuff if you have.
I have the following strange situation here I need some help with:
I am building a Qt application with MySQL access. For this I have:
- a dedicated building machine, using Qt 2010.05 and a MySQL 5.1 just for the libraries, Windows 7 32 bit. This machine creates the install package.
- a dedicated development machine, CentOS 5.5
- two testing machines:
- - an "always" fresh install of Windows 7
- - another Windows 7 machine with a newer Qt on it used for other stuff too.
I have built the previous version of the application sometime in February this year (on the bilding machine), it works nicely and perfectly, loads the MySQL driver (I have put it in the sqldrivers directory as indicated by everyone else). The install package installs, works everywhere (at least on all my Windows machines).
Now, I have built another release of the application, on the same machine. In the install package the only important difference is the executable (and some HTML files, but those are not relevant). Everything else is the same. When I run the NEW executable on the build machine I get ("QSQLITE", "QMYSQL3", "QMYSQL", "QODBC3", "QODBC") as the QSqlDatabase::drivers() output. If I run the NEW exectuable on any other machine I get an empty list of drivers. If I run the OLD package on any machine it works...
The loaded modules by the two processess (old executable, new executable) are basically the same, except is the qtmysql DLL which gets loaded in the old one and not in the new.
Have you ever encountered a situation like this? If yes do you have a feasible solution for it?
Thanks,
f.
Qt will only load plugins which are compatible with the program or version of Qt used. See the Deploying Plugins document.
You could also try using QPluginLoader to manually load a plugin and check what is reported as the QPluginLoader::errorString when it doesn't load (add the error message to your question if you can't fix it still).