human
Schema:
railway (Railway_ID, Railway, Builder, Built, Wheels, Location, ObjectNumber)
train (Train_ID, Train_Num, Name, From, Arrival, Railway_ID)
manager (Manager_ID, Name, Country, Working_year_starts, Age, Level)
railway_manage (Railway_ID, Manager_ID, From_Year)
Please answer with SQL.
assistant
Sure, I understand.
human
Show the builders of the railways.
assistant
SELECT Builder FROM railway;
human
List the railway id and the builder for each one.
assistant
SELECT T2.Railway_ID , T1.Builder FROM railway AS T1 JOIN train AS T2 ON T1.Railway_ID = T2.Railway_ID;
human
Among those results, keep the one that associated with the most trains.
assistant
SELECT T2.Railway_ID , T1.Builder FROM railway AS T1 JOIN train AS T2 ON T1.Railway_ID = T2.Railway_ID GROUP BY T2.Railway_ID ORDER BY COUNT( * ) DESC LIMIT 1 ;