c++ - QSqldriver 未加载，但可用

Question

我正在用 Qt 编写程序，但遇到了一个小问题。这编译得很好，但我有这个:

QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7

当我在 /opt/Qt/5.5/gcc_64/plugins/sqldrivers 中使用 ldd libqsqlmysql.so 时，我得到了这个:

./libqsqlmysql.so: /usr/lib/x86_64-linux-gnu/libmysqlclient_r.so.16: version `libmysqlclient_16' not found (required by ./libqsqlmysql.so)
linux-vdso.so.1 =>  (0x00007ffe02bb3000)
libmysqlclient_r.so.16 => /usr/lib/x86_64-linux-gnu/libmysqlclient_r.so.16 (0x00007fa3f8431000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007fa3f8217000)
libcrypt.so.1 => /lib/x86_64-linux-gnu/libcrypt.so.1 (0x00007fa3f7fde000)
libnsl.so.1 => /lib/x86_64-linux-gnu/libnsl.so.1 (0x00007fa3f7dc4000)
libssl.so.10 => not found
libcrypto.so.10 => not found
libQt5Sql.so.5 => /opt/Qt/5.5/gcc_64/plugins/sqldrivers/./../../lib/libQt5Sql.so.5 (0x00007fa3f7b83000)
libQt5Core.so.5 => /opt/Qt/5.5/gcc_64/plugins/sqldrivers/./../../lib/libQt5Core.so.5 (0x00007fa3f743d000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fa3f721e000)
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fa3f6e9c000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fa3f6b94000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fa3f697c000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fa3f65b2000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fa3f63ae000)
libicui18n.so.54 => /opt/Qt/5.5/gcc_64/plugins/sqldrivers/./../../lib/libicui18n.so.54 (0x00007fa3f5f3f000)
libicuuc.so.54 => /opt/Qt/5.5/gcc_64/plugins/sqldrivers/./../../lib/libicuuc.so.54 (0x00007fa3f5b91000)
libicudata.so.54 => /opt/Qt/5.5/gcc_64/plugins/sqldrivers/./../../lib/libicudata.so.54 (0x00007fa3f4166000)
libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007fa3f3f64000)
librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fa3f3d5c000)
libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007fa3f3a4d000)
/lib64/ld-linux-x86-64.so.2 (0x0000558b780a6000)
libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007fa3f37df000)

我的代码:

    QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
db.setHostName("hostname");
db.setDatabaseName("name");
db.setUserName("username");
db.setPassword("password");

问题是什么？

编辑:我尝试安装 openssl，但是当我编写 sudo apt-get install openssl 时，我得到了这个:

    Reading package lists... Done
Building dependency tree       
Reading state information... Done
openssl is already the newest version.
openssl set to manually installed.
The following packages were automatically installed and are no longer required:
  kde-l10n-engb kde-l10n-pl libdlrestrictions1 libkdecore5
  linux-headers-4.2.0-16 linux-headers-4.2.0-16-generic linux-headers-4.2.0-18
  linux-headers-4.2.0-18-generic linux-headers-4.2.0-19
  linux-headers-4.2.0-19-generic linux-image-4.2.0-16-generic
  linux-image-4.2.0-18-generic linux-image-4.2.0-19-generic
  linux-image-extra-4.2.0-16-generic linux-image-extra-4.2.0-18-generic
  linux-image-extra-4.2.0-19-generic linux-signed-image-4.2.0-16-generic
  linux-signed-image-4.2.0-18-generic linux-signed-image-4.2.0-19-generic
Use 'apt-get autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

下一步编辑:好的，我再次使用 ldd libqmysql.so 我得到了这个:

./libqsqlmysql.so: /usr/lib/x86_64-linux-gnu/libmysqlclient_r.so.16: version `libmysqlclient_16' not found (required by ./libqsqlmysql.so)
linux-vdso.so.1 =>  (0x00007ffdb25e9000)
libmysqlclient_r.so.16 => /usr/lib/x86_64-linux-gnu/libmysqlclient_r.so.16 (0x00007f54d5b3f000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f54d5925000)
libcrypt.so.1 => /lib/x86_64-linux-gnu/libcrypt.so.1 (0x00007f54d56ec000)
libnsl.so.1 => /lib/x86_64-linux-gnu/libnsl.so.1 (0x00007f54d54d2000)
libssl.so.10 => /lib/x86_64-linux-gnu/libssl.so.10 (0x00007f54d5269000)
libcrypto.so.10 => /lib/x86_64-linux-gnu/libcrypto.so.10 (0x00007f54d4e26000)
libQt5Sql.so.5 => /opt/Qt/5.5/gcc_64/plugins/sqldrivers/./../../lib/libQt5Sql.so.5 (0x00007f54d4be6000)
libQt5Core.so.5 => /opt/Qt/5.5/gcc_64/plugins/sqldrivers/./../../lib/libQt5Core.so.5 (0x00007f54d44a0000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f54d4281000)
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f54d3eff000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f54d3bf7000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f54d39df000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f54d3615000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f54d3411000)
libicui18n.so.54 => /opt/Qt/5.5/gcc_64/plugins/sqldrivers/./../../lib/libicui18n.so.54 (0x00007f54d2fa2000)
libicuuc.so.54 => /opt/Qt/5.5/gcc_64/plugins/sqldrivers/./../../lib/libicuuc.so.54 (0x00007f54d2bf4000)
libicudata.so.54 => /opt/Qt/5.5/gcc_64/plugins/sqldrivers/./../../lib/libicudata.so.54 (0x00007f54d11c9000)
libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007f54d0fc7000)
librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f54d0dbf000)
libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007f54d0aaf000)
/lib64/ld-linux-x86-64.so.2 (0x000055d80d1dc000)
libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f54d0842000)

Answer 1

sudo apt-get install openssl
cd /lib/x86_64-linux-gnu
sudo ln -s libssl.so.1.0.0 libssl.so.10
sudo ln -s libcrypto.so.1.0.0 libcrypto.so.10

并且，还要通知您的 Qt 经销商更改链接器。

注意

问题是 Qt 和你的 libmysqlclient 不兼容。现在，我们只能通过

安装 libmysqlclient18

apt-get install libmysqlclient18

而且它不会与您的 Qt 安装兼容，因为它需要版本 16。

我建议您升级您的 Qt 安装