How many repair assignments are there in file?
select count(*) from repair_assignment
What about in terms of technicians?
select technician_id, count(*) from repair_assignment group by technician_id
Show me their names instead of ids.
select t2.name, count(*) from repair_assignment as t1 join technician as t2 on t1.technician_id = t2.technician_id group by t2.name