$/*$

These tasks are done in "court" database, which you can download from Moodle.

Write you SQL code right after each task.

You must use the type of SQL command that is demanded. For example, using joins instead of subqueries

when subquery is expected, gives $0$ point.

Each task gives you $1$ point, $7$ points total.

$*/$

$--$ Task $1($Use Subqueries$)$: Find the names of employees $($first$\_$name, last$\_$name$)$ who work in the $\text{'}$IT$\text{'}$ department.

$--$ Your SQL here

$--$ Task $2($Use Subqueries$)$: List the projects $($project$\_$name$)$ located in the same city as the $\text{'}$IT$\text{'}$ department.

$--$ Your SQL here

$--$ Task $3($Use Subqueries$)$: Find the projects $($project$\_$name$)$ with more than $300$ total hours worked by employees.

$--$ Your SQL here

$--$ Task $4$: $($Use Subqueries$)$ List the employees $($first$\_$name, last$\_$name$)$ who have the highest salary within their department.

$--$ Your SQL here

$--$ Task $5($Use Subqueries$)$: Find all persons who have worked on at least one project located in HELSINKI.

$--$ Your SQL here

$--$ Task $6($Use Window Function$)$: Calculate the average tax rate for employees who have a degree $(\text{'}$BA$\text{'},\text{'}$MSc$\text{'},$ or $\text{'}$PhD$\text{'}).$

$--$ Your SQL here

$--$ Task $7($Use Window Function$)$: Rank employees by salary within each department

$--$ Your SQL here