How many engineer visits are required at most for a single fault log? List the number and the log entry id.
SELECT count ( * )  ,  T1.fault_log_entry_id FROM Fault_Log AS T1 JOIN Engineer_Visits AS T2 ON T1.fault_log_entry_id   =   T2.fault_log_entry_id GROUP BY T1.fault_log_entry_id ORDER BY count ( * )  DESC LIMIT 1
at most refers to MAX(count(*)); engineer visits are required for a single fault log refers to counting rows in Engineer_Visits that match a fault_log_entry_id in Fault_Log; list the number and the log entry id refers to SELECT count(*), fault_log_entry_id;