Table schema:
CREATE TABLE races (raceid VARCHAR); CREATE TABLE results (driverid VARCHAR, raceid VARCHAR); CREATE TABLE drivers (driverid VARCHAR)

Question: Find the driver id and number of races of all drivers who have at most participated in 30 races?
SQL: SELECT T1.driverid, COUNT(*) FROM drivers AS T1 JOIN results AS T2 ON T1.driverid = T2.driverid JOIN races AS T3 ON T2.raceid = T3.raceid GROUP BY T1.driverid HAVING COUNT(*) <= 30