MariaDB [textbook]> #7. List the slip number for every slip in marina 1 whose annual rental fee is less than $3,000.00.
MariaDB [textbook]> describe A_MARINA_SLIP;
+------------+--------------+------+-----+---------+-------+
| Field      | Type         | Null | Key | Default | Extra |
+------------+--------------+------+-----+---------+-------+
| SLIP_ID    | decimal(4,0) | NO   | PRI | NULL    |       |
| MARINA_NUM | char(4)      | YES  | MUL | NULL    |       |
| SLIP_NUM   | char(4)      | YES  |     | NULL    |       |
| LENGTH     | decimal(4,0) | YES  |     | NULL    |       |
| RENTAL_FEE | decimal(8,2) | YES  |     | NULL    |       |
| BOAT_NAME  | char(50)     | YES  |     | NULL    |       |
| BOAT_TYPE  | char(50)     | YES  |     | NULL    |       |
| OWNER_NUM  | char(4)      | YES  | MUL | NULL    |       |
+------------+--------------+------+-----+---------+-------+
8 rows in set (0.00 sec)

MariaDB [textbook]> select SLIP_NUM from A_MARINA_SLIP where RENTAL_FEE < 3000;
+----------+
| SLIP_NUM |
+----------+
| B1       |
| B2       |
| 1        |
| 2        |
| 3        |
| 4        |
+----------+
6 rows in set (0.00 sec)

MariaDB [textbook]> #8. Labor is billed at the rate of $60.00 per hour. List the slip ID, category number, estimated hours, and estimated labor cost for every service request. To obtain the estimated labor cost, multiply the estimated hours by 60. Use the column name ESTIMATED_COST for the esti- mated labor cost. 
MariaDB [textbook]> show tables;
+--------------------+
| Tables_in_textbook |
+--------------------+
| A_MARINA           |
| A_MARINA_SLIP      |
| A_OWNER            |
| A_SERVICE_CATEGORY |
| A_SERVICE_REQUEST  |
+--------------------+
5 rows in set (0.00 sec)

MariaDB [textbook]> describe A_SERVICE_REQUEST;
+-------------------+--------------+------+-----+---------+-------+
| Field             | Type         | Null | Key | Default | Extra |
+-------------------+--------------+------+-----+---------+-------+
| SERVICE_ID        | decimal(4,0) | NO   | PRI | NULL    |       |
| SLIP_ID           | decimal(4,0) | YES  |     | NULL    |       |
| CATEGORY_NUM      | decimal(4,0) | YES  | MUL | NULL    |       |
| DESCRIPTION       | char(255)    | YES  |     | NULL    |       |
| STATUS            | char(255)    | YES  |     | NULL    |       |
| EST_HOURS         | decimal(4,2) | YES  |     | NULL    |       |
| SPENT_HOURS       | decimal(4,2) | YES  |     | NULL    |       |
| NEXT_SERVICE_DATE | date         | YES  |     | NULL    |       |
+-------------------+--------------+------+-----+---------+-------+
8 rows in set (0.00 sec)

MariaDB [textbook]> #8. Labor is billed at the rate of $60.00 per hour. List the slip ID, category number, estimated hours, and estimated labor cost for every service request. To obtain the estimated labor cost, multiply the estimated hours by 60. Use the column name ESTIMATED_COST for the esti- mated labor cost. 
MariaDB [textbook]> select SLIP_ID, CATEGORY_NUM, EST_HOURS, EST_HOURS*60 as "ESTIMATED_COST"
    -> from A_SERVICE_REQUEST;
+---------+--------------+-----------+----------------+
| SLIP_ID | CATEGORY_NUM | EST_HOURS | ESTIMATED_COST |
+---------+--------------+-----------+----------------+
|       1 |            3 |      4.00 |         240.00 |
|       5 |            4 |      2.00 |         120.00 |
|       4 |            1 |      1.00 |          60.00 |
|       1 |            2 |      2.00 |         120.00 |
|       3 |            5 |      4.00 |         240.00 |
|      11 |            4 |      3.00 |         180.00 |
|       6 |            2 |      2.00 |         120.00 |
|       6 |            2 |      4.00 |         240.00 |
|       7 |            6 |      8.00 |         480.00 |
|       2 |            8 |      7.00 |         420.00 |
|       2 |            3 |      1.00 |          60.00 |
|       4 |            8 |      2.00 |         120.00 |
|       8 |            2 |      5.00 |         300.00 |
|       7 |            5 |      6.00 |         360.00 |
|      11 |            7 |      8.00 |         480.00 |
+---------+--------------+-----------+----------------+
15 rows in set (0.00 sec)

MariaDB [textbook]> #9. List the marina number and slip number for all slips containing a boat with the type Sprite 4000, Sprite 3000, or Ray 4025. 
MariaDB [textbook]> select MARINA_NUM, SLIP_NUM from A_MARINA_SLIP where BOAT_TYPE in ("Sprite 4000", "Sprite 3000", "Ray 4025" );
+------------+----------+
| MARINA_NUM | SLIP_NUM |
+------------+----------+
| 1          | A1       |
| 1          | A2       |
| 1          | A3       |
| 1          | B2       |
| 2          | 6        |
+------------+----------+
5 rows in set (0.00 sec)

MariaDB [textbook]> #10. How many Dolphin 25 boats are stored at both marina
MariaDB [textbook]> select count( * ) from A_MARINA_SLIP where BOAT_TYPE = "Dolphin 25";
+------------+
| count( * ) |
+------------+
|          2 |
+------------+
1 row in set (0.00 sec)

MariaDB [textbook]> notee;