Task: Text to Code
Input (English): Step 1: find the EMPLOYEE_ID of job_history table.
Step 2: find the average SALARY in employees table whose employees's EMPLOYEE_ID not one of the results of step 1
Output (English): SELECT Avg ( T1.SALARY ) FROM employees AS T1 WHERE T1.EMPLOYEE_ID NOT IN ( SELECT T2.EMPLOYEE_ID FROM job_history AS T2 )