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QSqlDatabase: QMYSQL driver not loaded / Build MySQL Plugin

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qmysqlsqlmoduleubuntu 14.04linux mint
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  • SGaistS Offline
    SGaistS Offline
    SGaist
    Lifetime Qt Champion
    wrote on last edited by
    #3

    Hi,

    It's more than just a number in your file name.

    Just rebuild the plugin using your currently installed MySQL library, it will be faster than trying to install version 16.

    Interested in AI ? www.idiap.ch
    Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

    M 2 Replies Last reply
    1
    • SGaistS SGaist

      Hi,

      It's more than just a number in your file name.

      Just rebuild the plugin using your currently installed MySQL library, it will be faster than trying to install version 16.

      M Offline
      M Offline
      mattewre
      wrote on last edited by mattewre
      #4
      This post is deleted!
      1 Reply Last reply
      0
      • SGaistS SGaist

        Hi,

        It's more than just a number in your file name.

        Just rebuild the plugin using your currently installed MySQL library, it will be faster than trying to install version 16.

        M Offline
        M Offline
        mattewre
        wrote on last edited by mattewre
        #5

        @SGaist updated the first post with the progress made with plugin build.

        1 Reply Last reply
        0
        • SGaistS Offline
          SGaistS Offline
          SGaist
          Lifetime Qt Champion
          wrote on last edited by
          #6

          You need to install the sources using the maintenance tool and call qmake from your Qt 5.5

          Interested in AI ? www.idiap.ch
          Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

          M 1 Reply Last reply
          0
          • SGaistS SGaist

            You need to install the sources using the maintenance tool and call qmake from your Qt 5.5

            M Offline
            M Offline
            mattewre
            wrote on last edited by mattewre
            #7

            @SGaist
            Thank for the tip about qmake.
            I have found and used the qmake from my Qt5.5 installation in /home/[myUsername]/Qt/5.5/gcc/bin/qmake
            Then I managed to run make too, so I think I successfully built the plugin.

            I have updated the first post, so other people can read it and follow step-by-step instruction. I'm not an expert of linux, so I you have some suggestion / improvements let me know and I'll edit the first post.

            1 Reply Last reply
            0
            • SGaistS Offline
              SGaistS Offline
              SGaist
              Lifetime Qt Champion
              wrote on last edited by
              #8

              You are doing something nasty: don't do the links to libmysqlclient_r yourself. You are missing the MySQL dev package. Install it and you're good to go.

              Interested in AI ? www.idiap.ch
              Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

              1 Reply Last reply
              0
              • B Offline
                B Offline
                bionegative
                wrote on last edited by bionegative
                #9

                Thank you, i manage to build the driver on one of my develop machines. However when i am doing the same on my other Linux machine it doesnt list it as an avaible driver even?
                [Qt run]
                QSqlDatabase: QMYSQL driver not loaded
                QSqlDatabase: available drivers: QSQLITE QODBC3 QODBC

                ~/Qt5.5.0/5.5/gcc_64/plugins/sqldrivers$ ls -l
                -rwxr-xr-x 1 user user 73368 okt 9 06:48 libqsqlmysql.so
                » shows its been newly built

                ldd libqsqlmysql.so
                libmysqlclient.so.18 => /usr/lib/x86_64-linux-gnu/libmysqlclient.so.18 (0x00007f6565b28000)
                » It have found the link

                » It seems like Qt dosnt know about it afterall.
                usualy qt's output list the driver atleast but doesnt show it as loaded untill its compiled.

                Edit: I tried load it during runtime
                [Qt]
                QPluginLoader loader;
                loader.load("TheFullFilePath");
                loader.errorString();
                » And it shows me this error: "The file '/home/..........libqsqlmysql.so' is not a valid Qt plugin.
                So something when wrong during building.

                FIXED:
                » This error was kinda fun, there was a manually added path variable in qtcreator->Tools->Options->Build & Run->[Tab]Qt Versons. Where the Auto-detected where right and the Manual was pointing at an old qt4 version.
                After deleting that and rebuild the driver it worked..

                1 Reply Last reply
                0
                • M Offline
                  M Offline
                  Malhar
                  wrote on last edited by
                  #10

                  Hi ,
                  i am facing a different kind of issue. after doing ldd to libqsqlmysql.so inside sqldrivers folder am unable to see
                  libmysqlclient_r.so.16 => not found this particular statement.
                  Please help and reply ASAP.

                  Thanks

                  1 Reply Last reply
                  0
                  • SGaistS Offline
                    SGaistS Offline
                    SGaist
                    Lifetime Qt Champion
                    wrote on last edited by
                    #11

                    Hi and welcome to devnet,

                    Then, what do you see ?

                    Interested in AI ? www.idiap.ch
                    Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                    M 1 Reply Last reply
                    0
                    • SGaistS SGaist

                      Hi and welcome to devnet,

                      Then, what do you see ?

                      M Offline
                      M Offline
                      Malhar
                      wrote on last edited by
                      #12

                      @SGaist After doing ldd libqmysqlclint.so got this

                      ldd libqsqlpsql.so
                      linux-vdso.so.1 => (0x00007ffd58adb000)
                      libpq.so.5 => /usr/lib/libpq.so.5 (0x00007f8a75afe000)
                      libQt5Sql.so.5 => /opt/Qt5.1.0/5.1.0/gcc_64/plugins/sqldrivers/./../../lib/libQt5Sql.so.5 (0x00007f8a758bf000)
                      libQt5Core.so.5 => /opt/Qt5.1.0/5.1.0/gcc_64/plugins/sqldrivers/./../../lib/libQt5Core.so.5 (0x00007f8a75236000)
                      libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f8a74f32000)
                      libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f8a74b6d000)
                      libssl.so.1.0.0 => /lib/x86_64-linux-gnu/libssl.so.1.0.0 (0x00007f8a7490e000)
                      libcrypto.so.1.0.0 => /lib/x86_64-linux-gnu/libcrypto.so.1.0.0 (0x00007f8a74533000)
                      libkrb5.so.3 => /usr/lib/x86_64-linux-gnu/libkrb5.so.3 (0x00007f8a74268000)
                      libcom_err.so.2 => /lib/x86_64-linux-gnu/libcom_err.so.2 (0x00007f8a74064000)
                      libgssapi_krb5.so.2 => /usr/lib/x86_64-linux-gnu/libgssapi_krb5.so.2 (0x00007f8a73e1e000)
                      libldap_r-2.4.so.2 => /usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2 (0x00007f8a73bcd000)
                      libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f8a739af000)
                      libicui18n.so.51 => /opt/Qt5.1.0/5.1.0/gcc_64/plugins/sqldrivers/./../../lib/libicui18n.so.51 (0x00007f8a73596000)
                      libicuuc.so.51 => /opt/Qt5.1.0/5.1.0/gcc_64/plugins/sqldrivers/./../../lib/libicuuc.so.51 (0x00007f8a73210000)
                      libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f8a7300c000)
                      libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007f8a72e0a000)
                      librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f8a72c02000)
                      libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007f8a728fa000)
                      libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f8a725f4000)
                      libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f8a723de000)
                      /lib64/ld-linux-x86-64.so.2 (0x00007f8a75f42000)
                      libk5crypto.so.3 => /usr/lib/x86_64-linux-gnu/libk5crypto.so.3 (0x00007f8a721af000)
                      libkrb5support.so.0 => /usr/lib/x86_64-linux-gnu/libkrb5support.so.0 (0x00007f8a71fa4000)
                      libkeyutils.so.1 => /lib/x86_64-linux-gnu/libkeyutils.so.1 (0x00007f8a71da0000)
                      libresolv.so.2 => /lib/x86_64-linux-gnu/libresolv.so.2 (0x00007f8a71b85000)
                      liblber-2.4.so.2 => /usr/lib/x86_64-linux-gnu/liblber-2.4.so.2 (0x00007f8a71976000)
                      libsasl2.so.2 => /usr/lib/x86_64-linux-gnu/libsasl2.so.2 (0x00007f8a7175b000)
                      libgssapi.so.3 => /usr/lib/x86_64-linux-gnu/libgssapi.so.3 (0x00007f8a7151d000)
                      libgnutls.so.26 => /usr/lib/x86_64-linux-gnu/libgnutls.so.26 (0x00007f8a7125f000)
                      libgcrypt.so.11 => /lib/x86_64-linux-gnu/libgcrypt.so.11 (0x00007f8a70fdf000)
                      libicudata.so.51 => /opt/Qt5.1.0/5.1.0/gcc_64/plugins/sqldrivers/./../../lib/libicudata.so.51 (0x00007f8a6f896000)
                      libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f8a6f658000)
                      libheimntlm.so.0 => /usr/lib/x86_64-linux-gnu/libheimntlm.so.0 (0x00007f8a6f44f000)
                      libkrb5.so.26 => /usr/lib/x86_64-linux-gnu/libkrb5.so.26 (0x00007f8a6f1c7000)
                      libasn1.so.8 => /usr/lib/x86_64-linux-gnu/libasn1.so.8 (0x00007f8a6ef26000)
                      libhcrypto.so.4 => /usr/lib/x86_64-linux-gnu/libhcrypto.so.4 (0x00007f8a6ecf3000)
                      libroken.so.18 => /usr/lib/x86_64-linux-gnu/libroken.so.18 (0x00007f8a6eade000)
                      libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f8a6e8c5000)
                      libtasn1.so.6 => /usr/lib/x86_64-linux-gnu/libtasn1.so.6 (0x00007f8a6e6b1000)
                      libp11-kit.so.0 => /usr/lib/x86_64-linux-gnu/libp11-kit.so.0 (0x00007f8a6e46f000)
                      libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007f8a6e26a000)
                      libwind.so.0 => /usr/lib/x86_64-linux-gnu/libwind.so.0 (0x00007f8a6e041000)
                      libheimbase.so.1 => /usr/lib/x86_64-linux-gnu/libheimbase.so.1 (0x00007f8a6de33000)
                      libhx509.so.5 => /usr/lib/x86_64-linux-gnu/libhx509.so.5 (0x00007f8a6dbea000)
                      libsqlite3.so.0 => /usr/lib/x86_64-linux-gnu/libsqlite3.so.0 (0x00007f8a6d931000)
                      libcrypt.so.1 => /lib/x86_64-linux-gnu/libcrypt.so.1 (0x00007f8a6d6f8000)
                      libffi.so.6 => /usr/lib/x86_64-linux-gnu/libffi.so.6 (0x00007f8a6d4f0000)

                      M 1 Reply Last reply
                      0
                      • M Malhar

                        @SGaist After doing ldd libqmysqlclint.so got this

                        ldd libqsqlpsql.so
                        linux-vdso.so.1 => (0x00007ffd58adb000)
                        libpq.so.5 => /usr/lib/libpq.so.5 (0x00007f8a75afe000)
                        libQt5Sql.so.5 => /opt/Qt5.1.0/5.1.0/gcc_64/plugins/sqldrivers/./../../lib/libQt5Sql.so.5 (0x00007f8a758bf000)
                        libQt5Core.so.5 => /opt/Qt5.1.0/5.1.0/gcc_64/plugins/sqldrivers/./../../lib/libQt5Core.so.5 (0x00007f8a75236000)
                        libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f8a74f32000)
                        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f8a74b6d000)
                        libssl.so.1.0.0 => /lib/x86_64-linux-gnu/libssl.so.1.0.0 (0x00007f8a7490e000)
                        libcrypto.so.1.0.0 => /lib/x86_64-linux-gnu/libcrypto.so.1.0.0 (0x00007f8a74533000)
                        libkrb5.so.3 => /usr/lib/x86_64-linux-gnu/libkrb5.so.3 (0x00007f8a74268000)
                        libcom_err.so.2 => /lib/x86_64-linux-gnu/libcom_err.so.2 (0x00007f8a74064000)
                        libgssapi_krb5.so.2 => /usr/lib/x86_64-linux-gnu/libgssapi_krb5.so.2 (0x00007f8a73e1e000)
                        libldap_r-2.4.so.2 => /usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2 (0x00007f8a73bcd000)
                        libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f8a739af000)
                        libicui18n.so.51 => /opt/Qt5.1.0/5.1.0/gcc_64/plugins/sqldrivers/./../../lib/libicui18n.so.51 (0x00007f8a73596000)
                        libicuuc.so.51 => /opt/Qt5.1.0/5.1.0/gcc_64/plugins/sqldrivers/./../../lib/libicuuc.so.51 (0x00007f8a73210000)
                        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f8a7300c000)
                        libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007f8a72e0a000)
                        librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f8a72c02000)
                        libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007f8a728fa000)
                        libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f8a725f4000)
                        libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f8a723de000)
                        /lib64/ld-linux-x86-64.so.2 (0x00007f8a75f42000)
                        libk5crypto.so.3 => /usr/lib/x86_64-linux-gnu/libk5crypto.so.3 (0x00007f8a721af000)
                        libkrb5support.so.0 => /usr/lib/x86_64-linux-gnu/libkrb5support.so.0 (0x00007f8a71fa4000)
                        libkeyutils.so.1 => /lib/x86_64-linux-gnu/libkeyutils.so.1 (0x00007f8a71da0000)
                        libresolv.so.2 => /lib/x86_64-linux-gnu/libresolv.so.2 (0x00007f8a71b85000)
                        liblber-2.4.so.2 => /usr/lib/x86_64-linux-gnu/liblber-2.4.so.2 (0x00007f8a71976000)
                        libsasl2.so.2 => /usr/lib/x86_64-linux-gnu/libsasl2.so.2 (0x00007f8a7175b000)
                        libgssapi.so.3 => /usr/lib/x86_64-linux-gnu/libgssapi.so.3 (0x00007f8a7151d000)
                        libgnutls.so.26 => /usr/lib/x86_64-linux-gnu/libgnutls.so.26 (0x00007f8a7125f000)
                        libgcrypt.so.11 => /lib/x86_64-linux-gnu/libgcrypt.so.11 (0x00007f8a70fdf000)
                        libicudata.so.51 => /opt/Qt5.1.0/5.1.0/gcc_64/plugins/sqldrivers/./../../lib/libicudata.so.51 (0x00007f8a6f896000)
                        libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f8a6f658000)
                        libheimntlm.so.0 => /usr/lib/x86_64-linux-gnu/libheimntlm.so.0 (0x00007f8a6f44f000)
                        libkrb5.so.26 => /usr/lib/x86_64-linux-gnu/libkrb5.so.26 (0x00007f8a6f1c7000)
                        libasn1.so.8 => /usr/lib/x86_64-linux-gnu/libasn1.so.8 (0x00007f8a6ef26000)
                        libhcrypto.so.4 => /usr/lib/x86_64-linux-gnu/libhcrypto.so.4 (0x00007f8a6ecf3000)
                        libroken.so.18 => /usr/lib/x86_64-linux-gnu/libroken.so.18 (0x00007f8a6eade000)
                        libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f8a6e8c5000)
                        libtasn1.so.6 => /usr/lib/x86_64-linux-gnu/libtasn1.so.6 (0x00007f8a6e6b1000)
                        libp11-kit.so.0 => /usr/lib/x86_64-linux-gnu/libp11-kit.so.0 (0x00007f8a6e46f000)
                        libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007f8a6e26a000)
                        libwind.so.0 => /usr/lib/x86_64-linux-gnu/libwind.so.0 (0x00007f8a6e041000)
                        libheimbase.so.1 => /usr/lib/x86_64-linux-gnu/libheimbase.so.1 (0x00007f8a6de33000)
                        libhx509.so.5 => /usr/lib/x86_64-linux-gnu/libhx509.so.5 (0x00007f8a6dbea000)
                        libsqlite3.so.0 => /usr/lib/x86_64-linux-gnu/libsqlite3.so.0 (0x00007f8a6d931000)
                        libcrypt.so.1 => /lib/x86_64-linux-gnu/libcrypt.so.1 (0x00007f8a6d6f8000)
                        libffi.so.6 => /usr/lib/x86_64-linux-gnu/libffi.so.6 (0x00007f8a6d4f0000)

                        M Offline
                        M Offline
                        Malhar
                        wrote on last edited by
                        #13

                        @SGaist sorry man that was my mistake i did ldd to a different .so file.

                        Thanks

                        1 Reply Last reply
                        0
                        • P Offline
                          P Offline
                          Peter Van Grieken
                          wrote on last edited by
                          #14

                          @mattewre: really good post! Tnx!
                          @SGaist: I've been reading the forums and noticed you've been answering a lot of question asked by beginners like me. Thank you for the support!!

                          This post really helped to understand this issue, but I've been trying to tackle the same problem for a few days now but for some reason I don't seem to be able to recompile the library "libqsqlmysql.so".

                          1. What I can see
                          • Compiling an application that uses mysql produces this output:

                          loaded library "/home/petervg/Qt5.5.1/5.5/gcc_64/plugins/sqldrivers/libqsqlmysql.so"
                          QLibraryPrivate::loadPlugin failed on "/home/petervg/Qt5.5.1/5.5/gcc_64/plugins/sqldrivers/libqsqlmysql.so" : "Cannot load library /home/petervg/Qt5.5.1/5.5/gcc_64/plugins/sqldrivers/libqsqlmysql.so: (libmysqlclient_r.so.16: cannot open shared object file: No such file or directory)"
                          QSqlDatabase: QMYSQL driver not loaded
                          QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7

                          • library:

                          I do have the file libmysqlclient_r.so.18 located in /usr/lib/
                          (note: I also have libmysqlclient_r.so.18.3.0 located in /usr/lib/ so during my frantic search for a solution I may have updated mysql again :-) ). I guess recompiling libqsqlmysql.so will link to the correct one?

                          • doublechecking library dependency

                          petervg@ubuntu:~/Qt5.5.1/5.5/gcc_64/plugins/sqldrivers$ ldd libqsqlmysql.so
                          linux-vdso.so.1 => (0x00007ffc493bf000)
                          libmysqlclient_r.so.16 => not found
                          libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f5ffbe74000)
                          libcrypt.so.1 => /lib/x86_64-linux-gnu/libcrypt.so.1 (0x00007f5ffbc3b000)
                          libnsl.so.1 => /lib/x86_64-linux-gnu/libnsl.so.1 (0x00007f5ffba21000)
                          libssl.so.10 => not found
                          libcrypto.so.10 => not found
                          libQt5Sql.so.5 => /home/petervg/Qt5.5.1/5.5/gcc_64/plugins/sqldrivers/./../../lib/libQt5Sql.so.5 (0x00007f5ffb7e0000)
                          libQt5Core.so.5 => /home/petervg/Qt5.5.1/5.5/gcc_64/plugins/sqldrivers/./../../lib/libQt5Core.so.5 (0x00007f5ffb09a000)
                          libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f5ffae7b000)
                          libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f5ffaaf9000)
                          libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f5ffa7f1000)
                          libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f5ffa5d9000)
                          libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f5ffa20f000)
                          libicui18n.so.54 => /home/petervg/Qt5.5.1/5.5/gcc_64/plugins/sqldrivers/./../../lib/libicui18n.so.54 (0x00007f5ff9da0000)
                          libicuuc.so.54 => /home/petervg/Qt5.5.1/5.5/gcc_64/plugins/sqldrivers/./../../lib/libicuuc.so.54 (0x00007f5ff99f2000)
                          libicudata.so.54 => /home/petervg/Qt5.5.1/5.5/gcc_64/plugins/sqldrivers/./../../lib/libicudata.so.54 (0x00007f5ff7fc8000)
                          libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f5ff7dc4000)
                          libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007f5ff7bc1000)
                          librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f5ff79b9000)
                          libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007f5ff76aa000)
                          /lib64/ld-linux-x86-64.so.2 (0x00005569bd500000)
                          libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f5ff743c000)

                          1. try to recompile libqsqlmysql.so from the source included with the offline installer.

                          petervg@ubuntu:~/Qt5.5.1/5.5/Src/qtbase/src/plugins/sqldrivers/mysql$ qmake
                          petervg@ubuntu:~/Qt5.5.1/5.5/Src/qtbase/src/plugins/sqldrivers/mysql$ make
                          rm -f libqsqlmysql.so
                          g++ -Wl,--no-undefined -Wl,-O1 -Wl,--enable-new-dtags -Wl,-rpath,/home/petervg/Qt5.5.1/5.5/gcc_64 -Wl,-rpath,/home/petervg/Qt5.5.1/5.5/gcc_64 -Wl,-rpath,/home/petervg/Qt5.5.1/5.5/gcc_64/lib -shared -o libqsqlmysql.so .obj/main.o .obj/qsql_mysql.o .obj/moc_qsql_mysql_p.o -rdynamic -L/usr/lib64/mysql -lz -lcrypt -lnsl -lm -lssl -lcrypto -L/home/petervg/Qt5.5.1/5.5/Src/qtbase/lib -lQt5Sql -L/usr/local/lib -lmysqlclient_r -lQt5Core -lpthread
                          /usr/bin/ld: cannot find -lQt5Sql
                          /usr/bin/ld: cannot find -lQt5Core

                          collect2: error: ld returned 1 exit status
                          Makefile:142: recipe for target '../../../../plugins/sqldrivers/libqsqlmysql.so' failed
                          make: *** [../../../../plugins/sqldrivers/libqsqlmysql.so] Error 1
                          petervg@ubuntu:~/Qt5.5.1/5.5/Src/qtbase/src/plugins/sqldrivers/mysql$

                          -> I'm not sure if this is relevant, but I can see the library Qt5Sql cannot be found even though in (1) i can see the library libQt5Sql.so.5 is found in /home/petervg/Qt5.5.1/5.5/gcc_64/lib.

                          1. try to recompile libqsqlmysql.so from the source I downloaded (qt-everywhere-opensource-src-5.5.1).

                          petervg@ubuntu:~/Downloads/qt-everywhere-opensource-src-5.5.1/qtbase/src/plugins/sqldrivers/mysql$ qmake
                          petervg@ubuntu:~/Downloads/qt-everywhere-opensource-src-5.5.1/qtbase/src/plugins/sqldrivers/mysql$ make
                          rm -f libqsqlmysql.so
                          g++ -Wl,--no-undefined -Wl,-O1 -Wl,--enable-new-dtags -Wl,-rpath,/home/petervg/Qt5.5.1/5.5/gcc_64 -Wl,-rpath,/home/petervg/Qt5.5.1/5.5/gcc_64 -Wl,-rpath,/home/petervg/Qt5.5.1/5.5/gcc_64/lib -shared -o libqsqlmysql.so .obj/main.o .obj/qsql_mysql.o .obj/moc_qsql_mysql_p.o -rdynamic -L/usr/lib64/mysql -lmysqlclient_r -lz -lcrypt -lnsl -lm -lssl -lcrypto -L/home/petervg/Downloads/qt-everywhere-opensource-src-5.5.1/qtbase/lib -lQt5Sql -lQt5Core -lpthread
                          /usr/bin/ld: cannot find -lQt5Sql
                          /usr/bin/ld: cannot find -lQt5Core

                          collect2: error: ld returned 1 exit status
                          Makefile:142: recipe for target '../../../../plugins/sqldrivers/libqsqlmysql.so' failed
                          make: *** [../../../../plugins/sqldrivers/libqsqlmysql.so] Error 1

                          -> identical results...

                          1. Conclusion

                          I've learned it's best to first make sure you have the latest mysql files installed before installing QT, so i guess I could completely reinstall Qt now, but I'ld like to learn what I have been doing wrong....

                          Any tips where I should look further?

                          With kind regards
                          Peter

                          1 Reply Last reply
                          0
                          • P Offline
                            P Offline
                            Peter Van Grieken
                            wrote on last edited by
                            #15

                            (answering myself :-) )

                            i open the mysql.pro in qtcreator (Coming from windows... I like an ide a lot more than the command line... sorry :-) ) and I added folowing line to this file:

                            LIBS += -L/home/petervg/Qt5.5.1/5.5/gcc_64/lib

                            I did this because I knew libQt5Sql.so.5 was located in /home/petervg/Qt5.5.1/5.5/gcc_64/lib.

                            What I do need to look into, is WHY this works? In /etc/environment I added:

                            • "PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/home/petervg/Qt5.5.1/Tools/QtCreator/bin/:/home/petervg/Qt5.5.1/5.5/gcc_64/lib:/home/petervg/Qt5.5.1/Tools/QtCreator/lib/qtcreator:/usr/lib"/x86_64-linux-gnu"

                            and in /home/petervg/.profile I added:

                            • LIBRARY_PATH="/home/petervg/Qt5.5.1/5.5/gcc_64/lib:/home/petervg/Qt5.5.1/5.5/gcc_64/plugins:/usr/lib/x86_64-linux-gnu:$LIBRARY_PATH"
                              LD_LIBRARY_PATH="/home/petervg/Qt5.5.1/5.5/gcc_64/lib:/home/petervg/Qt5.5.1/5.5/gcc_64/plugins:/usr/lib/x86_64-linux-gnu:$LD_LIBRARY_PATH"
                              export LIBRARY_PATH
                              export LD_LIBRARY_PATH

                            Neither of these solutions worked.

                            But my problem us finally solved, so up to the next one... If anybody could shed some light as to why adding the line in the .PRO file worked, but not when adding the path to the environment variables... I'll be glad to know...

                            Tnx!

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                            • SGaistS Offline
                              SGaistS Offline
                              SGaist
                              Lifetime Qt Champion
                              wrote on last edited by
                              #16

                              Hi,

                              The most simple way to ensure you're using the right qmake is to call it with the full path to the executable. One other problem comes from the fact that you also have Qt Creator's stuff in your PATH. Don't do it, Qt Creator comes with it's own build of Qt so that it's a complete autonomous application.

                              The LIBS += -L/path/ tells the linker where to look for libraries.

                              Interested in AI ? www.idiap.ch
                              Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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                              • P Offline
                                P Offline
                                Peter Van Grieken
                                wrote on last edited by
                                #17

                                Thanks!

                                I'll take a good look at the PATH variable.

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                                • SGaistS Offline
                                  SGaistS Offline
                                  SGaist
                                  Lifetime Qt Champion
                                  wrote on last edited by
                                  #18

                                  Leave it clean, that way you ensure that you're not mixing things on your system while building the driver.

                                  Interested in AI ? www.idiap.ch
                                  Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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                                  • RalfSchaeferR Offline
                                    RalfSchaeferR Offline
                                    RalfSchaefer
                                    wrote on last edited by
                                    #19

                                    Hi,

                                    i'm facing a similiar sort of problem, not completely solvable by the steps above.
                                    I recompiled the QMYSQL-plugin and it's linked to the correct mysql-libraries.
                                    After doing ldd /opt/Qt/5.5/gcc_64/plugins/sqldrivers/libqsqlmysql.so I got this:

                                    ldd /opt/Qt/5.5/gcc_64/plugins/sqldrivers/libqsqlmysql.so 
                                           linux-vdso.so.1 (0x00007fffd7d83000)
                                           libmysqlclient.so.18 => /usr/lib64/libmysqlclient.so.18 (0x00007f9eb8607000)
                                            libz.so.1 => /lib64/libz.so.1 (0x00007f9eb83f0000)
                                            libcrypt.so.1 => /lib64/libcrypt.so.1 (0x00007f9eb81b5000)
                                            libnsl.so.1 => /lib64/libnsl.so.1 (0x00007f9eb7f9d000)
                                            libssl.so.1.0.0 => /lib64/libssl.so.1.0.0 (0x00007f9eb7d34000)
                                            libcrypto.so.1.0.0 => /lib64/libcrypto.so.1.0.0 (0x00007f9eb7941000)
                                            libQt5Sql.so.5 => /opt/Qt/5.5/gcc_64/lib/libQt5Sql.so.5 (0x00007f9eb7701000)
                                            libQt5Core.so.5 => /opt/Qt/5.5/gcc_64/lib/libQt5Core.so.5 (0x00007f9eb6fba000)
                                            libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f9eb6d9d000)
                                            libstdc++.so.6 => /usr/lib64/libstdc++.so.6 (0x00007f9eb6a1b000)
                                            libm.so.6 => /lib64/libm.so.6 (0x00007f9eb6719000)
                                            libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f9eb6502000)
                                            libc.so.6 => /lib64/libc.so.6 (0x00007f9eb615b000)
                                            libdl.so.2 => /lib64/libdl.so.2 (0x00007f9eb5f56000)
                                            libicui18n.so.54 => /opt/Qt/5.5/gcc_64/lib/libicui18n.so.54 (0x00007f9eb5ae8000)
                                            libicuuc.so.54 => /opt/Qt/5.5/gcc_64/lib/libicuuc.so.54 (0x00007f9eb5739000)
                                            libicudata.so.54 => /opt/Qt/5.5/gcc_64/lib/libicudata.so.54 (0x00007f9eb3d0f000)
                                            libgthread-2.0.so.0 => /usr/lib64/libgthread-2.0.so.0 (0x00007f9eb3b0d000)
                                            librt.so.1 => /lib64/librt.so.1 (0x00007f9eb3904000)
                                            libglib-2.0.so.0 => /usr/lib64/libglib-2.0.so.0 (0x00007f9eb35f5000)
                                            /lib64/ld-linux-x86-64.so.2 (0x000055fc1f3d8000)
                                            libpcre.so.1 => /usr/lib64/libpcre.so.1 (0x00007f9eb338e000)
                                    

                                    So, erverything looks fine here.

                                    When I try to connect to the database, it still doesn't work. It seems, QSqlDatabase loads the plugin without problems, setting dabase specific stuff fails.

                                    My code-snippet, containing additional debug-stuff:

                                        QPluginLoader loader;
                                        loader.setFileName("/opt/Qt/5.5/gcc_64/plugins/sqldrivers/libqsqlmysql.so");
                                        qDebug() << "PluginLoader worked =" << loader.load();
                                        qDebug() << "Plugin Loader error=" << loader.errorString();
                                    
                                        QStringList driverlist =QSqlDatabase::drivers();
                                        qDebug() << "Databases: ";
                                        for (int i = 0; i < driverlist.size(); ++i)
                                        {
                                            qDebug() << driverlist.at(i);
                                        }
                                    
                                        if (!db_opened)
                                        {
                                                db = new QSqlDatabase();
                                                qDebug() << "Step 1 - Database:    is valid=" << db->isValid();
                                                db->addDatabase("QMYSQL3","cooptimedb");
                                                qDebug() << "Step 2 - Database:    is valid=" << db->isValid();
                                    
                                                db->setHostName("localhost");
                                                db->setDatabaseName("cooptime");
                                                db->setUserName("cooptime");
                                                db->setPassword("...");
                                                db->setPort(3306);
                                    
                                                qDebug() << "Database\n========\nHostname: " << db->hostName() << "\nDatabasename: " << db->databaseName() << "\nUsername: " << db->userName() << "\nPassword: " << db->password()  << "\nPort: " << db->port();
                                    
                                    
                                                if (! db->open())
                                                {
                                                    qDebug() << "db errorcode=" <<  db->lastError().nativeErrorCode();
                                                    qDebug() << "db errormessage=" << db->lastError() .text();
                                                }
                                    

                                    The output of the code above is:

                                    PluginLoader worked = true
                                    Plugin Loader error= "Unknown error"
                                    Databases: 
                                    "QSQLITE"
                                    "QMYSQL"
                                    "QMYSQL3"
                                    "QPSQL"
                                    "QPSQL7"
                                    Step 1 - Database:    is valid= false
                                    Step 2 - Database:    is valid= false
                                    Database
                                    ========
                                    Hostname:  "" 
                                    Databasename:  "" 
                                    Username:  "" 
                                    Password:  "" 
                                    Port:  -1
                                    db errorcode= ""
                                    db errormessage= "Driver not loaded Driver not loaded"
                                    

                                    So it seems, the driver still doesn't load.

                                    Any help would be very appreciated. Thanks in advance.

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                                    • SGaistS Offline
                                      SGaistS Offline
                                      SGaist
                                      Lifetime Qt Champion
                                      wrote on last edited by
                                      #20

                                      Hi and welcome to devnet,

                                      Your code is wrong, you are creating an invalid QSqlDatabase object on the heap and then you call a static function on it.

                                      Please take a look at QSqlDatabase's detailed documentation. There's an example there on how to do the setup and connection.

                                      Interested in AI ? www.idiap.ch
                                      Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                                      RalfSchaeferR 1 Reply Last reply
                                      0
                                      • SGaistS SGaist

                                        Hi and welcome to devnet,

                                        Your code is wrong, you are creating an invalid QSqlDatabase object on the heap and then you call a static function on it.

                                        Please take a look at QSqlDatabase's detailed documentation. There's an example there on how to do the setup and connection.

                                        RalfSchaeferR Offline
                                        RalfSchaeferR Offline
                                        RalfSchaefer
                                        wrote on last edited by
                                        #21

                                        @SGaist Thanks for your help!! That's it. Now all works fine for me!

                                        1 Reply Last reply
                                        0
                                        • fikou1335F Offline
                                          fikou1335F Offline
                                          fikou1335
                                          wrote on last edited by fikou1335
                                          #22

                                          Hi SGaist,

                                          I have a new problem with QMysql, everything worked fine since today, actually when I executede this line

                                              DB = QSqlDatabase::addDatabase( "QMYSQL");
                                          

                                          I have this error

                                          libgcc_s.so.1 must be installed for pthread_cancel to work
                                          

                                          I don't know why,

                                          the plugin is correctly compiled without error, and using the ldd he found the libgcc_s.so.1

                                          Can you help me please!

                                          1 Reply Last reply
                                          0

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