Once after updating the ABillS billing system, when opening the Maintenance>Hardware>PON menu and selecting a device, an SQL error occurred:
SQL Error:  [1176/main, ../../Abills/modules/Equipment/Pon_mng.pm, 674] Key 'port_id' doesn't exist in table 'onu' ...
Embedded script did not fix the error:
cd /usr/abills/misc/db_check/ ./db_check.pl
Therefore, I had to add the key manually:
ALTER TABLE equipment_pon_onu ADD KEY port_id (`port_id`);
A little later, another error occurred:
Key 'port' doesn't exist in table 'internet'
Was solved by adding the key:
ALTER TABLE `internet_main` ADD KEY port_id (`port`);