Error Connecting to PostgreSQL Mac OS

GBRITO

Hi, I am trying to connect a Qt Application with PostgreSQL on a Mac running Big Sur (intel), my simple code is as follow:

QSqlDatabase db = QSqlDatabase::addDatabase("QPSQL");
db.setHostName("localhost");
db.setDatabaseName("EAPDB");
db.setUserName("user");
db.setPassword("pass");
db.setPort(5432);

if (db.open())
    ui->lblTest->setText("Connected");
else
    ui->lblTest->setText("Not Connected");

When I try to run the program the following error appears:
Undefined symbols for architecture x86_64

I follow instructions to change the path using install_name_tool but doesn't work.

Hope one of you can help me.

GBRITO

Thanks @Christian-Ehrlicher for you guide, I read about linking the components and now the initial error about Undefined symbols for architecture x86_64 was fixed.

I add the links to the CMakeLists.txt as follows:

find_package(Qt6 REQUIRED COMPONENTS Sql)
target_link_libraries(EAPSolution PRIVATE Qt${QT_VERSION_MAJOR}::Widgets PRIVATE Qt${QT_VERSION_MAJOR}::Sql)

jsulm

@GBRITO said in Error Connecting to PostgreSQL Mac OS:

When I try to run the program the following error appears:
Undefined symbols for architecture x86_64

You mean when you try to build your application?
Please post the whole error.

GBRITO

@jsulm, you're right, the error appears when I try to build the applications, below is a screenshot of the complete error:

Thanks for your help

Christian Ehrlicher

So do you actually link against to Qt Sql module?

GBRITO

@Christian-Ehrlicher

I'm not sure about your question, I'm beginner in Qt, I follow internet guide how to connect from Qt to PostgreSQL, also when I found the problem I tried to solve it using the install_name_tool in order to tell Qt to use the PostgreSQL drivers. But the error continues.

Using the sqlbrowser application I have another error message, I know is not part of the application I'm trying to create, but that error leads me to use the install_name_tool.

In this application the PostgreSQL library is detected...

Christian Ehrlicher

@GBRITO said in Error Connecting to PostgreSQL Mac OS:

I'm beginner in Qt,

This is nothing Qt specific - if you use an external class then you must link against the library it contains. And each Qt class has a nice header which explains on how to do it. See e.g. QSqlDatabase.

The QPSQL driver not loaded problem should be solved afterwards - one at a time.

GBRITO

Thanks @Christian-Ehrlicher for you guide, I read about linking the components and now the initial error about Undefined symbols for architecture x86_64 was fixed.

I add the links to the CMakeLists.txt as follows:

find_package(Qt6 REQUIRED COMPONENTS Sql)
target_link_libraries(EAPSolution PRIVATE Qt${QT_VERSION_MAJOR}::Widgets PRIVATE Qt${QT_VERSION_MAJOR}::Sql)