$5.$

Write an SQL query for the HAPPY INSURANCE database that will display the average

rating for all agents.

$6.$

Write an SQL query for the HAPPY INSURANCE database that will for each area display the

area ID and the number of agents in the area.

$7.$

Write an SQL statement for the HAPPY INSURANCE database that adds the column

ClientPhone to the table CLIENT.

$8.$

Write an SQL query for the HAPPY INSURANCE database that will, for each agent, retrieve

the name of the agent and the name of his or her supervisor. $($The name of the agent will be

retrieved even if he or she has no supervisor.$)$

$9.$

Write an SQL query for the HAPPY INSURANCE database that will retrieve the name of each

client that has no spouse.

$10.$

Explain inner, left, right, full and self join.