[SOLVED] QSqlDatabase: QMYSQL driver not loaded with QMYSQL driver available in OSX Mavericks

SGaist

Check both Qt's MySQL plugin and libmysqlclient with otool -L to ensure that everything can be found correctly

Orbotron

Re: [SOLVED] QSqlDatabase: QMYSQL driver not loaded with QMYSQL driver available in OSX Mavericks

Just wanted to reply 2 years later to let people know that this solution still works on OSX if you download the offline installer qt-opensource for Mac OSX.

Thanks!

I ran otool on my libsqlmysql.dylib and it was pointing at

[dank:...clang_64/plugins/sqldrivers]$ otool -L libqsqlmysql.dylib
libqsqlmysql.dylib:
	libqsqlmysql.dylib (compatibility version 0.0.0, current version 0.0.0)
	/opt/local/lib/mysql55/mysql/libmysqlclient.18.dylib (compatibility version 18.0.0, current version 18.0.0)
	/usr/lib/libz.1.dylib (compatibility version 1.0.0, current version 1.2.5)
	@rpath/QtSql.framework/Versions/5/QtSql (compatibility version 5.5.0, current version 5.5.1)
	...

I install MySQL with Homebrew

[dank:...clang_64/plugins/sqldrivers]$ l /usr/local/lib/ | grep 18
drwxrwxr-x   32 root  admin   1.1K Feb 10 18:49 ..
drwxr-xr-x    3 dank  admin   102B Nov 18 12:35 python2.7
lrwxr-xr-x    1 dank  admin    52B Jan 29 13:11 utf8_and_gb18030.so -> ../Cellar/postgresql94/9.4.5/lib/utf8_and_gb18030.so
[dank:...clang_64/plugins/sqldrivers]$ l /usr/local/lib/ | grep mysql
lrwxr-xr-x    1 dank  admin    20B Feb  8 08:21 lib -> /usr/local/mysql/lib
lrwxr-xr-x    1 dank  admin    50B Feb  8 08:15 libmysqlclient.20.dylib -> ../Cellar/mysql/5.7.11/lib/libmysqlclient.20.dylib
lrwxr-xr-x    1 dank  admin    43B Feb  8 08:15 libmysqlclient.a -> ../Cellar/mysql/5.7.11/lib/libmysqlclient.a
lrwxr-xr-x    1 dank  admin    47B Feb  8 08:15 libmysqlclient.dylib -> ../Cellar/mysql/5.7.11/lib/libmysqlclient.dylib
lrwxr-xr-x    1 dank  admin    38B Feb  8 08:22 libmysqld-debug.a -> /usr/local/mysql/lib/libmysqld-debug.a
lrwxr-xr-x    1 dank  admin    38B Feb  8 08:15 libmysqld.a -> ../Cellar/mysql/5.7.11/lib/libmysqld.a
lrwxr-xr-x    1 dank  admin    45B Feb  8 08:15 libmysqlservices.a -> ../Cellar/mysql/5.7.11/lib/libmysqlservices.a
...

so I ran

install_name_tool -change /opt/local/lib/mysql55/mysql/libmysqlclient.18.dylib /usr/local/Cellar/mysql/5.7.11/lib/libmysqlclient.20.dylib libqsqlmysql.dylib

to double check

[dank:...clang_64/plugins/sqldrivers]$ otool -L libqsqlmysql.dylib
libqsqlmysql.dylib:
	libqsqlmysql.dylib (compatibility version 0.0.0, current version 0.0.0)
	/usr/local/Cellar/mysql/5.7.11/lib/libmysqlclient.20.dylib (compatibility version 18.0.0, current version 18.0.0)
	/usr/lib/libz.1.dylib (compatibility version 1.0.0, current version 1.2.5)
	@rpath/QtSql.framework/Versions/5/QtSql (compatibility version 5.5.0, current version 5.5.1)
	@rpath/QtCore.framework/Versions/5/QtCore (compatibility version 5.5.0, current version 5.5.1)
	/System/Library/Frameworks/DiskArbitration.framework/Versions/A/DiskArbitration (compatibility version 1.0.0, current version 1.0.0)
	/System/Library/Frameworks/IOKit.framework/Versions/A/IOKit (compatibility version 1.0.0, current version 275.0.0)
	/usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 120.0.0)
	/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1213.0.0)

I feel the fact that it still says version 18.0.0 is weird but it works now for me

Day Reloader

Hello SGiant, I am new to QT and have been trying to work with database using MYSQL for last few days, but am getting the same errors as others, i.e. "Driver not loaded Driver not loaded".
I tried copying libmysqlclient.20.dylib from ~/usr/local/Cellar/mysql/5.7.19/lib to ~/opt/local/lib/mysql55/mysql but nothing happened. (I don't know how to use install_name_tool).

Please help me out.
Thank You.

SGaist

Hi @Day-Reloader and welcome to devnet,

There's an example of how to use install_name_tool in this very thread in one of the answer of @Orbotron.

? Offline

I have a new problem. When I type "otool -L libqsqlmysql.dylib" in the terminal, the reply is /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/objdump: 'libqsqlmysql.dylib': No such file or directory
However, the fact is I have the file "libqsqlmysql.dylib" in the sqldrivers.
How do I solve this problem?

SGaist

Hi and welcome to devnet,

Either you have to be in the same folder as the file you want to analyse or pass the full path to it.

? Offline

@SGaist
amazing!! I have finished that step. But what about the next step?
I have searched the Internet about the some approaches to solve the driver problem, but I don't know which is correct.
PLZ

? Offline

@SGaist more details:
~/Qt/5.11.0/clang_64/plugins/sqldrivers  otool -L libqsqlmysql.dylib
libqsqlmysql.dylib:
libqsqlmysql.dylib (compatibility version 0.0.0, current version 0.0.0)
@rpath/QtSql.framework/Versions/5/QtSql (compatibility version 5.11.0, current version 5.11.0)
@rpath/QtCore.framework/Versions/5/QtCore (compatibility version 5.11.0, current version 5.11.0)
/System/Library/Frameworks/DiskArbitration.framework/Versions/A/DiskArbitration (compatibility version 1.0.0, current version 1.0.0)
/System/Library/Frameworks/IOKit.framework/Versions/A/IOKit (compatibility version 1.0.0, current version 275.0.0)
/usr/local/mysql/lib/libmysqlclient.20.dylib (compatibility version 20.0.0, current version 20.0.0)
/usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 307.5.0)
/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1238.50.2)

SGaist

The output looks nice. What is the problem ?

? Offline

I don't know the problems exactly. However ,I use the approaches which was published in the stackoverflow to solve this question.
I typed the phrase"install_name_tool -change libmysqlclient.20.dylib /usr/local/mysql/lib/libmysqlclient.20.dylib libqsqlmysql.dylib" in the Terminal, and then it worked!!!!!!
When I connect MySql to QT, I faced the problem about the permission. Then I changed the "hostname" and in the last , I can use QT to edit the Mysql database.
Thx!!!!