What is the percentage of all the trains with at least 4 cars? List the directions of the said trains.
at least 4 cars refers to trailPosi > = 4; calculation = MULTIPLY(DIVIDE(count(trailPosi > = 4 then id), count(id)), 100)
SELECT CAST(COUNT(CASE WHEN T2.trailPosi >= 4 THEN T1.id ELSE NULL END) AS REAL) * 100 / COUNT(T1.id) FROM trains AS T1 INNER JOIN ( SELECT train_id, MAX(position) AS trailPosi FROM cars GROUP BY train_id ) AS T2 ON T1.id = T2.train_id UNION ALL SELECT T1.direction FROM trains AS T1 INNER JOIN ( SELECT train_id, MAX(position) AS trailPosi FROM cars t GROUP BY train_id ) AS T2 ON T1.id = T2.train_id AND T2.trailPosi >= 4
database name:db_id trains
cars table cars Cols: id dtype integer, train id dtype integer, position dtype integer, shape dtype text, length dtype text, sides dtype text, roof dtype text, wheels dtype integer, load_shape dtype text, load number dtype integer, 
trains table trains Cols: id dtype integer, direction dtype text, 
