/usr/lib/x86_64-linux-gnu/libmysqlcppconn.so.7 is in libmysqlcppconn7v5 1.1.9-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libmysqlcppconn.so.7.1.1.9
/usr/lib/x86_64-linux-gnu/libmysqlcppconn.so.7.1.1.9