Qt5 and PostgreSQL

  • Sorry, but this is application development and thus beyond the support for technical questions. So F&S can not help here. But maybe other customers.


    Your F&S Support Team

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.

  • I answer myself, and to people who have this problem in the future:


    I was not able to find Qt5 PostgreSQL (nor another database) plugin in buildroot packages menu, but, it is! Target packages -> Graphic libraries and applications (graphic/text) -> Qt5 -> qt5base -> PostgreSQL Plugin.


    If you navigate to that path you will not see the plugin, and there is no way to find it through the buildroot search.


    What I have done to find and install the plugin is to search the parent level (qt5base) in buildroot search, and you will see the "hidden" packages.


    I do not know if this is a bug when looking for a package, but this is a strange way to find it.

  • I do not understand this. if you configure your Buildroot with fsimx6_qt5_defconfig and build this environment, then Qt5 is already active and you can see the "PostgreSQL Plugin" in "Target packages" -> "Graphic libraries and applications (graphic/text)" -> "Qt5". In other words if you did not see this, then you most probably have configured Qt5 in a wrong way anyway. So please make sure that your environment is actually based on fsimx6_qt5_defconfig if you use Qt5, not on fsimx6_std_defconfig.


    The menuconfig system (also called Kconfig system) has two different systems to activate options that depend on other options. By using "selects" and by using "depends on". The first method automatically selects one or more additional entries if the current entry is activated. This works well for small entities, for example to also activate a library that is necessary to build a larger application. However this system has two drawbacks. First you often do not see what actually gets activated because the selected item is not in the same menu. So you have no visual feedback on how much other stuff this current entry will "pull in". And second, If you disable the entry again, the selected entries may not automatically be deselected again, too. It actually works if you are still in the same invocation of menuconfig, but this cross-information is lost if you save the state and restart menuconfig. So features using this method tend to leave items behind, that are activated but unused, which results in unnecessary large root filesystems.


    The second method "depends on" is commonly used for larger sub-systems. It means that some sub-entries will only get visible if the parent entry is activated. For example it only makes sense to show all the X11 applications if you actually have activated X11. Or like in this case, it makes only sense to show all the Qt5 applications if you actually have activated Qt5. The drawback here is that you sometimes do not know what items you need to activate to get to see the item that you are looking for.


    If you know the name of your option, then you can use the search '/'. Enter a part of the name and then you will see all matching entries, also those that would currently not be visible. There you will see in the "Depends on" section what items need to be activated to see the item in question. It also shows the place in the menu hierarchy where the item is located and (in current menuconfig versions) you can even jump directly to this entry by pressing the number key that is given in parenthesis.


    Your F&S Support Team

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.