Solved Qt Mac version doesn't have file libqsqlmysql.dylib

[Quang Phu]

Hi all,

I am developing an app connect to database use MySQL, this is my code

    QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
    db.setHostName("localhost");
    db.setUserName("root");
    db.setPassword("");
    db.setDatabaseName("user_temp");

but got error
QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QODBC QODBC3 QPSQL QPSQL7

I search for solution with this command:

install_name_tool -change /usr/local/mysql/lib/libmysqlclient.21.dylib /usr/local/mysql-8.0.17-macos10.14-x86_64/lib/libmysqlclient.21.dylib /Users/macbook/Qt5.13.0/5.13.0/clang_64/plugins/sqldrivers/libqsqlmysql.dylib

But It got error:

error: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/install_name_tool: can't open file: /Users/macbook/Qt5.13.0/5.13.0/clang_64/plugins/sqldrivers/libqsqlmysql.dylib (No such file or directory)

I check sqldrivers folder this is I have:

It seem miss libqsqlmysql.dylib file
So, how can I get this file to run?
This is my info:
Qt: 5.13.0
MacOS: 10.14.6

Thank you

[SGaist]

Hi,

The most simple would be to build the plugin following the documentation.

[Quang Phu]

Hi @SGaist
I tried to build plugin as document with these command

qmake -- MYSQL_PREFIX=/usr/local
make sub-mysql

but It seem incorrect syntax for qmake because I got these errors:

and

macbooks-MBP:sqldrivers macbook$ make sub-mysql
make: *** No rule to make target `sub-mysql'.  Stop.

This is my qmake version:

macbooks-MBP:sqldrivers macbook$ qmake -version
QMake version 3.1
Using Qt version 5.13.0 in /Users/macbook/Qt5.13.0/5.13.0/clang_64/lib

Did I miss anything, or i have to install more components?

Thank again!

[SGaist]

Looks like you didn't install the sources, did you ?

[Quang Phu]

Hi @SGaist,
I have checked my folder, when I run command in Src, qmake -- MYSQL_PREFIX=/usr/local seem work fine
but when I run
make sub-mysql
got error

make: *** No rule to make target `sub-mysql'.  Stop.

I tried to edit rerun qmake with path MYSQL_PREFIX=/usr/local/sql
Error still exists, and this if my folder structure
So what is incorrect here?

[SGaist]

Did you saw any error when calling qmake ?

From the looks of it, I would have thought that your MySQL installation is rather in the mysql subfolder.

[Quang Phu]

Hi @SGaist,
I think not.
Let make it easy, I'll show you all steps and log for this issue:

1. In uninstall mysql and Qt from my MacBook
2. I install mysql through file "mysql-8.0.17-macos10.14-x86_64.dmg" downloaded from mysql home page. As I know, this is latest release version of mysql.
   Installation success! Then I have 2 folder in /usr/local/
   /mysql/
   /mysql-8.0.17-macos10.14-x86_64/
3. I install Qt 5.13.0 through file "qt-opensource-mac-x64-5.13.0.dmg", I installed all components, and it success
4. I cd to Qt5.13.0/5.13.0/Src/qtbase/plugins/sqldrivers/ and run command:
   "qmake -- MYSQL_PREFIX=/usr/local/mysql"
   and I got this log
   

then I run
make sub-mysql
and got this error

I searched in Internet and in topic https://forum.qt.io/topic/99565/error-to-build-the-qmysql-plugin-on-macos-high-sierra/8

I have command:
configure -sql-mysql MYSQL_PREFIX=/usr/local/mysql

After running, I got this log

It seem Qt had driver mysql, then I go back Qt5.13.0/5.13.0/Src/qtbase/plugins/sqldrivers/
and try to run make sub-mysql, now no error appears and I have this log:

It seem ok, but in folder Qt5.13.0/5.13.0/clang_64/plugins/sqldrivers/, there is still no file libqsqlmysql.dylib.
And I run app still got error
QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QODBC QODBC3 QPSQL QPSQL7
Are there anything wrong here?
Thank @SGaist

[SGaist]

In the first case, based on the summary, MySQL has not been found since the MySql line clearly says no, hence the error you have after. As to why it failed to find it, take a look at the test logs.

As for the seconde case, you have your build of Qt installed in /usr/local/Qt-5.13.0. You will find there the MySQL plugin.

[Quang Phu]

I try make install as log, but got error
clang: error: no such file or directory: '/Users/macbook/Qt5.13.0/5.13.0/Src/qtbase/lib/libqtpcre2_debug.a'
make[4]: *** [../../lib/QtCore.framework/QtCore_debug] Error 1
make[3]: *** [debug-install] Error 2
make[2]: *** [sub-corelib-install_subtargets] Error 2
make[1]: *** [sub-src-install_subtargets] Error 2
hmm, it seem be hard, I think qt should provide more detail direction to install Mysql plugin. I saw many topics on Forum about this issue, but still can not find correct one for my case, thank again @SGaist

[SGaist]

I suggested to look at the test logs that are generated when you called qmake in the plugin folder. There you'll find what went wrong.

Note that since you have full Qt build with the MySQL plugin enabled, you can also use that one.

[Quang Phu]

Hi, @SGaist ,
Finally, it's done for me, but it takes time too much, I have look at many topics to find out solution for this. I think we should have a big topic to collect common issues + solution for each, it would reduce time for developer to search and supporter to answer.
Thank you for your support.
Between, I created a topic to give some instructions to create Mysql on Mac device at: https://forum.qt.io/topic/106565/mysql-qt-create-plugin-mysql-for-qt-on-mac, if you have time, please take a look at it, thanks.