MySql and Android

RenanHm

Hello.. Any updates on the MySql plugin on Android?

I managed to compile the MySql plugin... but when the lib is added to the Android project, there is an APP execution error. He follows:

ANDROID_EXTRA_LIBS += C:\mysqlarm64\lib\libmysqlclient.so

The application opens and closes with error. It does not report the error.

Am I using the wrong MySql library?
I downloaded the files from: https://dev.mysql.com/downloads/mysql/5.5.html?os=31&version=5.1

Is there already any solution to access MySQL from Android?

jsulm

@RenanHm said in MySql and Android:

Is there already any solution to access MySQL from Android?

I'm wondering what the use case is? Why do you want to access MySql server directly from an Android app?

RenanHm

Good Morning. I know the safest way is through a RES API or webservice. But in this specific case I need to connect directly to MySql through Android.

jsulm

@RenanHm Did you try to remote debug your app on Android to get more information about the issue?

RenanHm

Hello.. so, I use QT 5.14.2 and Windows 10.

I have successfully compiled the MySql plugin:

The file "libplugins_sqldrivers_qsqlmysql_arm64-v8a.so" is generated successfully.

When fetching the drivers through the function " QStringList drivers = QSqlDatabase::drivers();
" the driver "QMYSQL" is successfully found.

But when adding the library "libmysqlclient.so" an error occurs when opening the APP on Android.
No error appears. Simply open and immediately close the APP.

Now I ask: Is it possible to generate the plugin this way?
Is the MySql library correct? Or should other files be included as well?
Or just using MariaDB for MySQL access? (But I didn't find the arm64 libraries for MariaDB).

RenanHm

@jsulm Is there a way to debug this error??

RenanHm

I managed to debug.. it returns me the following error:

I Qt : qt started
E AndroidRuntime: FATAL EXCEPTION: qtMainLoopThread
E AndroidRuntime: Process: com.digitalsof.totallocapp, PID: 29087
E AndroidRuntime: java.lang.UnsatisfiedLinkError: dlopen failed: library "libpthread.so.0" not found: needed by /data/app/~~JWWP6Bwj6ZX5zMzQ0Fn3_g==/com.digitalsof.totallocapp-OqCdR438GzfaRWbmqFz5wg==/lib/arm64/libmysqlclient.so in namespace classloader-namespace
E AndroidRuntime: at java.lang.Runtime.load0(Runtime.java:929)
E AndroidRuntime: at java.lang.System.load(System.java:1625)
E AndroidRuntime: at org.qtproject.qt5.android.QtNative$3.run(QtNative.java:239)
E AndroidRuntime: at org.qtproject.qt5.android.QtThread$2.run(QtThread.java:87)
E AndroidRuntime: at org.qtproject.qt5.android.QtThread$1.run(QtThread.java:61)
E AndroidRuntime: at java.lang.Thread.run(Thread.java:1012)
19:30:21: Debugging has finished

"com.digitalsof.totallocapp" died.

Help??

jsulm

@RenanHm said in MySql and Android:

E AndroidRuntime: java.lang.UnsatisfiedLinkError: dlopen failed: library "libpthread.so.0" not found: needed by /data/app/~~JWWP6Bwj6ZX5zMzQ0Fn3_g==

This is your issue. I'm not an Android expert, so do not know whether Android provides pthread library. Try to deploy it with your application.

RenanHm

@jsulm Hello.. Okay. But where to find this "libpthread.so.0" arm64 library? I'm looking on Google and I didn't find it.. only 64-bit versions for linux distributions.
MySql files do not have this library.

jsulm

@RenanHm As I wrote: I do not know whether this lib is distributed with Android. But you can check in Android NDK or directly on Android device.

RenanHm

@jsulm Hello.. unfortunately I can't find it.. it's not inside the Android NDK and it's not inside my Android phone.
Searching a lot on Google I find only .RPM packages from some linux distributions. I do not know what to do.