MariaDB [(none)]> create database Practicaf;
Query OK, 1 row affected (0.005 sec)

MariaDB [(none)]> use Practicaf;
Database changed
MariaDB [Practicaf]> create table estudiante
    -> (Carnet varchar(10) not null,
    -> Nombre varchar(25) not null,
    -> Fecha_matricula date,
    -> Fecha_nacimiento date,
    -> sexo varchar(1) not null);
Query OK, 0 rows affected (0.046 sec)

MariaDB [Practicaf]> create table materia
    -> (Codigo_Materia varchar(5) not null,
    -> Descripcion varchar(20) not null,
    -> Valor int(10) not null);
Query OK, 0 rows affected (0.047 sec)

MariaDB [Practicaf]> create table Estu_Mate
    -> (Carnet varchar(5) not null,
    -> Codigo_Materia varchar(5) not null);
Query OK, 0 rows affected (0.036 sec)

MariaDB [Practicaf]> insert into estudiante(Carnet,Nombre,Fecha_matricula,Fecha_nacimiento,sexo)values ("001", "maria", "2010-01-15", "1966-05-13", "f"), ("002", "juana", "2010-06-08", "1973-01-22","f"), ("003", "carlos", "2010-06-28" , "1976-03-05" ,"m"), ("004" ,"Maria Parra", "2010-06-11", "1976-08-15","f"), ("005", "Pablo Neruda", "2011-02-13", "1990-08-25", "m"), ("006", "Bladimir Palacio", "2011-02-04" ,"1994-09-03" , "m"), ("007", "Apolonia Serrano", "2011-02-28" ,"1994-03-09" ,"f"), ( "008", "Federico Serrano","2011-03-05","1991-06-10",  "m");
Query OK, 8 rows affected (0.065 sec)
Records: 8  Duplicates: 0  Warnings: 0

MariaDB [Practicaf]> insert into materia(Codigo_Materia,Descripcion,Valor) values ("001", "software I", 320000 ), ("002","software II", 328000),("003","software III", 400000), ("004","matematicas",300000),("005", "ingles", 300000);
Query OK, 5 rows affected (0.017 sec)
Records: 5  Duplicates: 0  Warnings: 0

MariaDB [Practicaf]> insert into Estu_Mate(Carnet,Codigo_Materia) values ("1","3"),("1", "5"),( "2","2"),("2", "3"),("2","4"),("3" ,"4"),("3", "1" ),( "4", "4"),( "4", "5"),( "5", "2"),("5", "5"),("6", "1" ),("6" , "5" ),("7" ,"3"),("7","4"),("8", "1"),("8","4"),("8", "5");
Query OK, 18 rows affected (0.018 sec)
Records: 18  Duplicates: 0  Warnings: 0

MariaDB [Practicaf]> select * from estudiante;
+--------+------------------+-----------------+------------------+------+
| Carnet | Nombre           | Fecha_matricula | Fecha_nacimiento | sexo |
+--------+------------------+-----------------+------------------+------+
| 001    | maria            | 2010-01-15      | 1966-05-13       | f    |
| 002    | juana            | 2010-06-08      | 1973-01-22       | f    |
| 003    | carlos           | 2010-06-28      | 1976-03-05       | m    |
| 004    | Maria Parra      | 2010-06-11      | 1976-08-15       | f    |
| 005    | Pablo Neruda     | 2011-02-13      | 1990-08-25       | m    |
| 006    | Bladimir Palacio | 2011-02-04      | 1994-09-03       | m    |
| 007    | Apolonia Serrano | 2011-02-28      | 1994-03-09       | f    |
| 008    | Federico Serrano | 2011-03-05      | 1991-06-10       | m    |
+--------+------------------+-----------------+------------------+------+
8 rows in set (0.000 sec)

MariaDB [Practicaf]> select * from materia;
+----------------+--------------+--------+
| Codigo_Materia | Descripcion  | Valor  |
+----------------+--------------+--------+
| 001            | software I   | 320000 |
| 002            | software II  | 328000 |
| 003            | software III | 400000 |
| 004            | matematicas  | 300000 |
| 005            | ingles       | 300000 |
+----------------+--------------+--------+
5 rows in set (0.000 sec)

MariaDB [Practicaf]> select * from Estu_Mate;
+--------+----------------+
| Carnet | Codigo_Materia |
+--------+----------------+
| 1      | 3              |
| 1      | 5              |
| 2      | 2              |
| 2      | 3              |
| 2      | 4              |
| 3      | 4              |
| 3      | 1              |
| 4      | 4              |
| 4      | 5              |
| 5      | 2              |
| 5      | 5              |
| 6      | 1              |
| 6      | 5              |
| 7      | 3              |
| 7      | 4              |
| 8      | 1              |
| 8      | 4              |
| 8      | 5              |
+--------+----------------+
18 rows in set (0.000 sec)

MariaDB [Practicaf]> select count(*)"Numero_de_estudiantes" from estudiante where year(Fecha_nacimiento) between "1970" and "1979";
+-----------------------+
| Numero_de_estudiantes |
+-----------------------+
|                     3 |
+-----------------------+
1 row in set (0.000 sec)

MariaDB [Practicaf]> select Nombre from estudiante where year(current_date()) - year(Fecha_nacimiento) between "16" and "20";
Empty set (0.000 sec)

MariaDB [Practicaf]> select Nombre from estudiante where year(current_date()) - year(Fecha_nacimiento) > "25";
+------------------+
| Nombre           |
+------------------+
| maria            |
| juana            |
| carlos           |
| Maria Parra      |
| Pablo Neruda     |
| Bladimir Palacio |
| Apolonia Serrano |
| Federico Serrano |
+------------------+
8 rows in set (0.000 sec)

MariaDB [Practicaf]> select Nombre, year(current_date()) - year(Fecha_Nacimiento) "Edad" from estudiante;
+------------------+------+
| Nombre           | Edad |
+------------------+------+
| maria            |   58 |
| juana            |   51 |
| carlos           |   48 |
| Maria Parra      |   48 |
| Pablo Neruda     |   34 |
| Bladimir Palacio |   30 |
| Apolonia Serrano |   30 |
| Federico Serrano |   33 |
+------------------+------+
8 rows in set (0.000 sec)

MariaDB [Practicaf]> exit