1)
SELECT
    COUNT(*) "Nume incepe cu K"
FROM
    employees
WHERE
    last_name LIKE 'K%';

2)
SELECT
    employee_id,
    first_name,
    last_name
FROM
    employees
WHERE
    salary = (
        SELECT
            MIN(salary)
        FROM
            employees
    );
3)
SELECT
    unique(d.manager_id),
    e.first_name
FROM
    departments d,
    employees   e
WHERE
        d.department_id = 30
    AND d.manager_id IN (
        SELECT
            manager_id
        FROM
            employees
    );
4) INCOMPLET
SELECT
    employee_id,
    last_name,
    first_name
FROM
    employees e
JOIN departments d ON e.manager_id = d.manager_id;


5) SELECT
    e1.employee_id,
    e1.last_name,
    e1.first_name
FROM
         employees e1
    JOIN employees e2 ON ( e1.employee_id != e2.employee_id
                           AND e1.last_name = e2.last_name );

6) SELECT
    department_id,
    department_name
FROM
    departments
WHERE
    (
        SELECT
            COUNT(*)
        FROM
                 jobs j1
            JOIN jobs j2 ON j1.job_title != j2.job_title
    ) >= 2;

7)
SELECT
    qty
FROM
    orders_tbl,
    products_tbl
WHERE
    lower(prod_desc) LIKE '%plastic%';
8)
9)
10)
SELECT
    c.cust_name
FROM
         customer_tbl c
    JOIN orders_tbl o ON c.cust_id = o.cust_id
                         AND EXTRACT(DAY FROM o.ord_date) = 17;
11)
SELECT
    last_name,
    first_name,
    salary,
    bonus
FROM
    employee_tbl,
    employee_pay_tbl
WHERE
    32000 > greatest(salary, bonus * 17);