Each primary key is specified with a key icon.

The one$-$to$-$many relationships are specified by using

Note that in this question, the names of foreign key are coincidentally the same as the names

of primary key being referenced.

Write SQL commands to answer the following queries.

$($c$)$ Write a query to get the average salary for all departments employing more than $10$

employees. List the department ID$,$ average salary for the department and the

number of employees in the department.

$(3$ marks$)$

$($d$)$ Write a query to find the name $($first$\_$name, last$\_$name$)$ and the salary of the

employees who have a higher salary than the employee whose employee ID is $101.$

$($Hint: use sub$-$query$)$

$(3$ marks$)$