[Qt-interest] QMYSQLDriver - linking plugin's dynamic library

[Piotr Dąbrowski]

Hello,


I'm trying to use QSqlDatabase::addDatabase() to access an
already-open MySQL connection:
http://doc.qt.nokia.com/latest/qsqldatabase.html#addDatabase-2

Documentation says it is recommended to include driver's source file,
which I don't want. It requires choosing a single version of Qt and
may be acceptable for binary applications, but not for source
distribution.

I tried including only the header file (QtSql/qsql_mysql.h) and
linking the binary against plugins/sqldrivers/libqsqlmysql.so library
(cmake):


[...]

find_library (QT_QSQLMYSQL_LIBRARY qsqlmysql)
if (QT_QSQLMYSQL_LIBRARY)
	message (STATUS "Found QMYSQLDriver library: ${QT_QSQLMYSQL_LIBRARY}")
else (QT_QSQLMYSQL_LIBRARY)
	message (FATAL_ERROR "Could not find QMYSQLDriver library")
endif (QT_QSQLMYSQL_LIBRARY)

target_link_libraries (sql_history ${QT_QTSQL_LIBRARIES}
${MYSQL_LIBRARIES} ${QT_QSQLMYSQL_LIBRARY})


but I still get linking error:


symbol lookup error: /.../libsql_history.so: undefined symbol:
_ZN12QMYSQLDriverC1EP8st_mysqlP7QObject


Adding


#include <QtPlugin>
Q_IMPORT_PLUGIN(qsqlmysql)


results in another error:


undefined symbol: _Z28qt_plugin_instance_qsqlmysqlv


Am I doing something wrong?
How should this be done?