Consider the following database. Employee has a unique eid, name, age and salary. Department has a unique did, name and an employee as a manager. A department may or may not have a manager assigned. An employee can work for multiple departments. The pct_time in Works table is the percentage of time an employee works for a department. The salary of the employees is fixed and is not based on pct_time or the deparments they work in.

Emp (eid: INT(11), ename: VARCHAR(50), age: INT(11), salary: FLOAT)

Works (eid: INT(11), did: INT(11), pct_time: INT(11))

Dept (did: INT(11), dname: VARCHAR(50, managerid: INT(11))

Constraints

-eid is primary key for Emp table and cannot be NULL

-did is primary key for Dept table and cannot be NULL

-eid and did are foreign keys referencing to Emp and Dept tables respectively in Works table. combination of eid and did is the primary key or works table.

-managerid is foreign key referencing to Emp table and can have NULL values if the department doesnt have a manager assigned.

Sample values.

Emp

eid	ename	age	salary
1001	Georgi Facello	34	45000.00
1002	Parto Bamford	28	34000.00
1003	Christian Koblick	42	55000.00
1004	Saniya Peac	24	28000.00

Dept

did	dname	managerid
d001	Marketing	1003
d002	Finance	1002
d003	Information Security	NULL

Works

eid	did	pct_time
1001	d001	60
1002	d002	100
1003	d001	100
1001	d003	40
1004	d003	50
1004	d002	50

1. Create a new database named employee_db. Write the SQL statements required to create the above relations, including appropriate versions of all primary and foreign key integrity constraints. Submit all create table statements.

2. Write the insert statements to enter the above sample values to the database. Add 4 more employees, 2 more departments and assign the 4 new employees to departments with percentage time. Submit all insert statements.

3. Alter the table Emp to change the column age to dob with data type DATE and update the values based on their current age (should be approximate). Submit the alter and update table statement.

Write SQL queries for the following. Submit all queries. (5 points each)

1.Find the total salary of all employees.

2.Select the name and salary of the employee with the highest salary.

3.Select the department name and their respective manager name.

4.Select the employee names and their department names of the employees who work less than 50% of the time in that department.

5.Select the employee name and no of departments each employee works for.

6.Select the employee names with salary greater than average salary of all employees.

7.Select the department names with no manager assigned yet.

8.Select the employee names who work for more than 1 department.

9.Select the employee names and their manager names (keep in mind, one employee works for multiple departments so they will have multiple managers).

10.Select the name and salary of the employee with the second highest salary.