If cPanel does not show any databases in the datbases >> Mysql Datbases list then obvious thing we do is , execute command

#/usr/local/cpanel/bin/setupdbmap
But if /usr/local/cpanel/bin/setupdbmap shows following error,
isweak is only available with the XS version of Scalar::Util at /usr/local/cpanel/Cpanel/Class/Meta/Class.pm line 7
BEGIN failed--compilation aborted at /usr/local/cpanel/Cpanel/Class/Meta/Class.pm line 7.
Compilation failed in require at /usr/lib/perl5/site_perl/5.8.8/i386-linux-thread-multi/Cpanel/Class.pm line 8.
BEGIN failed--compilation aborted at /usr/lib/perl5/site_perl/5.8.8/i386-linux-thread-multi/Cpanel/Class.pm line 8.
Compilation failed in require at /usr/local/cpanel/Cpanel/DB/Mysql/Binaries.pm line 8.
BEGIN failed--compilation aborted at /usr/local/cpanel/Cpanel/DB/Mysql/Binaries.pm line 8.
Compilation failed in require at /usr/local/cpanel/Cpanel/DB/Mysql/Connection.pm line 8.
BEGIN failed--compilation aborted at /usr/local/cpanel/Cpanel/DB/Mysql/Connection.pm line 8.
Compilation failed in require at /usr/local/cpanel/bin/setupdbmap line 15.
BEGIN failed--compilation aborted at /usr/local/cpanel/bin/setupdbmap line 15.
Then do the following

#/scripts/upcp --force
#/scripts/checkperlmodules --force
#/usr/local/cpanel/bin/setupdbmap