/usr/lib/x86_64-linux-gnu/libmysqlcppconn.so is in libmysqlcppconn-dev 1.1.7-4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libmysqlcppconn.so.7
/usr/lib/x86_64-linux-gnu/libmysqlcppconn.so.7