Database problem--higher than the department's average salary query __ database

Title: Identify the employee's name, salary, department number, and average wage in the department above the average wage in the department

The structure of the table (table name is Sqltest)

1, first find out the average wage of each department

SELECT AVG (Salary) Avg_salary, depart_id from Sqltest GROUP by depart_id

Get

2, as a temporary table (temp_table), placed in the main query

Select Sqltest.name,sqltest.salary,temp_table.depart_id,temp_table.avg_salary 
from Sqltest, (select AVG (Salary  Avg_salary, depart_id from Sqltest GROUP by depart_id) temp_table
WHERE sqltest.depart_id = temp_table.depart_id and Sqltest.salary > Temp_table.avg_salary;

Get