CREATE TABLE employees (job_id VARCHAR)
CREATE TABLE jobs (job_title VARCHAR, job_id VARCHAR)

display job title and average salary of employees.
SELECT job_title, AVG(salary) FROM employees AS T1 JOIN jobs AS T2 ON T1.job_id = T2.job_id GROUP BY T2.job_title
SELECT "job_title", AVG("salary") FROM "employees" AS "T1" JOIN "jobs" AS "T2" ON "T1"."job_id" = "T2"."job_id" GROUP BY "T2"."job_title"