MariaDB [(none)]> create database fechas;
ERROR 1007 (HY000): Can't create database 'fechas'; database exists
MariaDB [(none)]> create database fechas001;
Query OK, 1 row affected (0.00 sec)

MariaDB [(none)]> use fechas001;
Database changed
MariaDB [fechas001]> show databases;
+--------------------+
| Database           |
+--------------------+
| academico          |
| aplicacion_cadena  |
| comercial          |
| consulta_externa   |
| facturacion        |
| fechas             |
| fechas001          |
| information_schema |
| institucion        |
| institucion1       |
| libreria           |
| matricula2         |
| mysql              |
| performance_schema |
| phpmyadmin         |
| secundaria         |
| test               |
| urgencias          |
+--------------------+
18 rows in set (0.00 sec)

MariaDB [fechas001]> Create table estudiante (carnet char(3) not null primary key, nombre varchar(50) not null, fechamatricula date not null, fechanacimiento date not null, sexo char(1) not null);
Query OK, 0 rows affected (0.34 sec)

MariaDB [fechas001]> describe estudiante;
+-----------------+-------------+------+-----+---------+-------+
| Field           | Type        | Null | Key | Default | Extra |
+-----------------+-------------+------+-----+---------+-------+
| carnet          | char(3)     | NO   | PRI | NULL    |       |
| nombre          | varchar(50) | NO   |     | NULL    |       |
| fechamatricula  | date        | NO   |     | NULL    |       |
| fechanacimiento | date        | NO   |     | NULL    |       |
| sexo            | char(1)     | NO   |     | NULL    |       |
+-----------------+-------------+------+-----+---------+-------+
5 rows in set (0.08 sec)

MariaDB [fechas001]> Create table materia (codigom char(3) not null primary key, descripcion varchar(50) not null, valor float not null);
Query OK, 0 rows affected (0.16 sec)

MariaDB [fechas001]> describe materia;
+-------------+-------------+------+-----+---------+-------+
| Field       | Type        | Null | Key | Default | Extra |
+-------------+-------------+------+-----+---------+-------+
| codigom     | char(3)     | NO   | PRI | NULL    |       |
| descripcion | varchar(50) | NO   |     | NULL    |       |
| valor       | float       | NO   |     | NULL    |       |
+-------------+-------------+------+-----+---------+-------+
3 rows in set (0.05 sec)

MariaDB [fechas001]> Create table estmat (carnet char(3) not null, codigom char(3) not null, PRIMARY KEY (carnet, codigom), FOREIGN KEY (carnet) REFERENCES estudiante (carnet) ON DELETE CASCADE ON UPDATE CASCADE, FOREIGN KEY (codigom) REFERENCES materia (codigom) ON DELETE CASCADE ON UPDATE CASCADE);
Query OK, 0 rows affected (0.21 sec)

MariaDB [fechas001]> describe esmat;
ERROR 1146 (42S02): Table 'fechas001.esmat' doesn't exist
MariaDB [fechas001]> describe estmat;
+---------+---------+------+-----+---------+-------+
| Field   | Type    | Null | Key | Default | Extra |
+---------+---------+------+-----+---------+-------+
| carnet  | char(3) | NO   | PRI | NULL    |       |
| codigom | char(3) | NO   | PRI | NULL    |       |
+---------+---------+------+-----+---------+-------+
2 rows in set (0.07 sec)

MariaDB [fechas001]> insert into estudiante(carnet, nombre, fechamatricula, fechanacimiento, sexo) values ('001','maria','2010-01-15','1966-05-13','f');
Query OK, 1 row affected (0.08 sec)

MariaDB [fechas001]> insert into estudiante(carnet, nombre, fechamatricula, fechanacimiento, sexo) values ('002','juana','2010-06-08','1973-01-22','f');
Query OK, 1 row affected (0.05 sec)

MariaDB [fechas001]> insert into estudiante(carnet, nombre, fechamatricula, fechanacimiento, sexo) values ('003','carlos','2010-06-28','1976-03-05','m');
Query OK, 1 row affected (0.09 sec)

MariaDB [fechas001]> insert into estudiante(carnet, nombre, fechamatricula, fechanacimiento, sexo) values ('004','Maria Parra','2010-06-11','1976-08-15','f');
Query OK, 1 row affected (0.07 sec)

MariaDB [fechas001]> insert into estudiante(carnet, nombre, fechamatricula, fechanacimiento, sexo) values ('005','Pablo Neruda','2011-02-13','1990-08-25','m');
Query OK, 1 row affected (0.03 sec)

MariaDB [fechas001]> insert into estudiante(carnet, nombre, fechamatricula, fechanacimiento, sexo) values ('006','Bladimir Palacio','2011-02-04','1994-09-03','m');
Query OK, 1 row affected (0.09 sec)

MariaDB [fechas001]> nsert into estudiante(carnet, nombre, fechamatricula, fechanacimiento, sexo) values ('007','Apolonia Serrano','2011-02-28','1994-03-09','f');
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'nsert into estudiante(carnet, nombre, fechamatricula, fechanacimiento, sexo) val' at line 1
MariaDB [fechas001]> insert into estudiante(carnet, nombre, fechamatricula, fechanacimiento, sexo) values ('007','Apolonia Serrano','2011-02-28','1994-03-09','f');
Query OK, 1 row affected (0.11 sec)

MariaDB [fechas001]> insert into estudiante(carnet, nombre, fechamatricula, fechanacimiento, sexo) values ('008','Federico Serrano','2011-03-05','1991-06-10','m');
Query OK, 1 row affected (0.09 sec)

MariaDB [fechas001]> select * from estudiante;
+--------+------------------+----------------+-----------------+------+
| carnet | nombre           | fechamatricula | fechanacimiento | 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 (0.00 sec)

MariaDB [fechas001]> insert into materia (codigom, descripcion, valor) values ('001','software I',320000);
Query OK, 1 row affected (0.08 sec)

MariaDB [fechas001]> insert into materia (codigom, descripcion, valor) values ('002','software II',328000);
Query OK, 1 row affected (0.10 sec)

MariaDB [fechas001]> insert into materia (codigom, descripcion, valor) values ('003','software III',400000);
Query OK, 1 row affected (0.09 sec)

MariaDB [fechas001]> insert into materia (codigom, descripcion, valor) values ('004','matematicas',300000);
Query OK, 1 row affected (0.08 sec)

MariaDB [fechas001]> insert into materia (codigom, descripcion, valor) values ('005','ingles',300000);
Query OK, 1 row affected (0.07 sec)

MariaDB [fechas001]> describe materia;
+-------------+-------------+------+-----+---------+-------+
| Field       | Type        | Null | Key | Default | Extra |
+-------------+-------------+------+-----+---------+-------+
| codigom     | char(3)     | NO   | PRI | NULL    |       |
| descripcion | varchar(50) | NO   |     | NULL    |       |
| valor       | float       | NO   |     | NULL    |       |
+-------------+-------------+------+-----+---------+-------+
3 rows in set (0.03 sec)

MariaDB [fechas001]> select * from materia;
+---------+--------------+--------+
| codigom | descripcion  | valor  |
+---------+--------------+--------+
| 001     | software I   | 320000 |
| 002     | software II  | 328000 |
| 003     | software III | 400000 |
| 004     | matematicas  | 300000 |
| 005     | ingles       | 300000 |
+---------+--------------+--------+
5 rows in set (0.04 sec)

MariaDB [fechas001]>  insert into estmat (carnet, codigom) values ('001','003');
Query OK, 1 row affected (0.04 sec)

MariaDB [fechas001]> insert into estmat (carnet, codigom) values ('001','005');
Query OK, 1 row affected (0.05 sec)

MariaDB [fechas001]> insert into estmat (carnet, codigom) values ('002','002');
Query OK, 1 row affected (0.08 sec)

MariaDB [fechas001]> insert into estmat (carnet, codigom) values ('002','003');
Query OK, 1 row affected (0.10 sec)

MariaDB [fechas001]> insert into estmat (carnet, codigom) values ('002','004');
Query OK, 1 row affected (0.05 sec)

MariaDB [fechas001]> insert into estmat (carnet, codigom) values ('003','004');
Query OK, 1 row affected (0.12 sec)

MariaDB [fechas001]> insert into estmat (carnet, codigom) values ('003','001');
Query OK, 1 row affected (0.05 sec)

MariaDB [fechas001]> insert into estmat (carnet, codigom) values ('004','004');
Query OK, 1 row affected (0.10 sec)

MariaDB [fechas001]> insert into estmat (carnet, codigom) values ('004','005');
Query OK, 1 row affected (0.08 sec)

MariaDB [fechas001]>  insert into estmat (carnet, codigom) values ('005','002');
Query OK, 1 row affected (0.08 sec)

MariaDB [fechas001]> insert into estmat (carnet, codigom) values ('005','005');
Query OK, 1 row affected (0.12 sec)

MariaDB [fechas001]> insert into estmat (carnet, codigom) values ('006','001');
Query OK, 1 row affected (0.07 sec)

MariaDB [fechas001]> insert into estmat (carnet, codigom) values ('006','005');
Query OK, 1 row affected (0.05 sec)

MariaDB [fechas001]> insert into estmat (carnet, codigom) values ('007','003');
Query OK, 1 row affected (0.10 sec)

MariaDB [fechas001]> insert into estmat (carnet, codigom) values ('007','004');
Query OK, 1 row affected (0.11 sec)

MariaDB [fechas001]> insert into estmat (carnet, codigom) values ('008','001');
Query OK, 1 row affected (0.10 sec)

MariaDB [fechas001]> insert into estmat (carnet, codigom) values ('008','004');
Query OK, 1 row affected (0.11 sec)

MariaDB [fechas001]> insert into estmat (carnet, codigom) values ('008','005');
Query OK, 1 row affected (0.07 sec)

MariaDB [fechas001]> select * from estmat;
+--------+---------+
| carnet | codigom |
+--------+---------+
| 001    | 003     |
| 001    | 005     |
| 002    | 002     |
| 002    | 003     |
| 002    | 004     |
| 003    | 001     |
| 003    | 004     |
| 004    | 004     |
| 004    | 005     |
| 005    | 002     |
| 005    | 005     |
| 006    | 001     |
| 006    | 005     |
| 007    | 003     |
| 007    | 004     |
| 008    | 001     |
| 008    | 004     |
| 008    | 005     |
+--------+---------+
18 rows in set (0.00 sec)

MariaDB [fechas001]> select count(*) from estudiante where year(fechanacimiento) between 1970 and 1979;
+----------+
| count(*) |
+----------+
|        3 |
+----------+
1 row in set (0.04 sec)

MariaDB [fechas001]> select  from estudiante where year(fechanacimiento) between 1970 and 1979; 
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'from estudiante where year(fechanacimiento) between 1970 and 1979' at line 1
MariaDB [fechas001]> select * from estudiante where year(fechanacimiento) between 1970 and 1979; 
+--------+-------------+----------------+-----------------+------+
| carnet | nombre      | fechamatricula | fechanacimiento | sexo |
+--------+-------------+----------------+-----------------+------+
| 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    |
+--------+-------------+----------------+-----------------+------+
3 rows in set (0.00 sec)

MariaDB [fechas001]> select * From estudiante Where Year(Current_date()) - year(fechanacimiento) Between 16 and 20;
Empty set (0.05 sec)

MariaDB [fechas001]> select nombre From estudiante Where Year(Current_date()) - year(fechanacimiento) > 25;
+------------------+
| nombre           |
+------------------+
| maria            |
| juana            |
| carlos           |
| Maria Parra      |
| Pablo Neruda     |
| Federico Serrano |
+------------------+
6 rows in set (0.00 sec)

MariaDB [fechas001]> select carnet, Nombre, Year(Current_date()) - year(fechanacimiento) 'Edad' From estudiante;
+--------+------------------+------+
| carnet | Nombre           | Edad |
+--------+------------------+------+
| 001    | maria            |   53 |
| 002    | juana            |   46 |
| 003    | carlos           |   43 |
| 004    | Maria Parra      |   43 |
| 005    | Pablo Neruda     |   29 |
| 006    | Bladimir Palacio |   25 |
| 007    | Apolonia Serrano |   25 |
| 008    | Federico Serrano |   28 |
+--------+------------------+------+
8 rows in set (0.00 sec)

MariaDB [fechas001]> select codigom, descripcion, valor, if(valor > 300000, 'Cara', 'Economica') As 'Categoria' from materia;
+---------+--------------+--------+-----------+
| codigom | descripcion  | valor  | Categoria |
+---------+--------------+--------+-----------+
| 001     | software I   | 320000 | Cara      |
| 002     | software II  | 328000 | Cara      |
| 003     | software III | 400000 | Cara      |
| 004     | matematicas  | 300000 | Economica |
| 005     | ingles       | 300000 | Economica |
+---------+--------------+--------+-----------+
5 rows in set (0.04 sec)

MariaDB [fechas001]> ALTER TABLE estudiante ADD Edad int NULL;
Query OK, 0 rows affected (0.53 sec)
Records: 0  Duplicates: 0  Warnings: 0

MariaDB [fechas001]> update estudiante set edad = Year(Current_date()) - year(fechanacimiento);
Query OK, 8 rows affected (0.09 sec)
Rows matched: 8  Changed: 8  Warnings: 0

MariaDB [fechas001]> select carnet, Nombre, edad, if(edad > 30, 'hombre mayor', 'joven en desarrollo') As 'Tipo' from estudiante;
+--------+------------------+------+---------------------+
| carnet | Nombre           | edad | Tipo                |
+--------+------------------+------+---------------------+
| 001    | maria            |   53 | hombre mayor        |
| 002    | juana            |   46 | hombre mayor        |
| 003    | carlos           |   43 | hombre mayor        |
| 004    | Maria Parra      |   43 | hombre mayor        |
| 005    | Pablo Neruda     |   29 | joven en desarrollo |
| 006    | Bladimir Palacio |   25 | joven en desarrollo |
| 007    | Apolonia Serrano |   25 | joven en desarrollo |
| 008    | Federico Serrano |   28 | joven en desarrollo |
+--------+------------------+------+---------------------+
8 rows in set (0.00 sec)

MariaDB [fechas001]> select codigom, descripcion, valor, if(valor > 200000 and valor <= 300000, 'Economica', if(valor > 300000, 'Cara', 'Otro')) As 'Categoria' from materia;
+---------+--------------+--------+-----------+
| codigom | descripcion  | valor  | Categoria |
+---------+--------------+--------+-----------+
| 001     | software I   | 320000 | Cara      |
| 002     | software II  | 328000 | Cara      |
| 003     | software III | 400000 | Cara      |
| 004     | matematicas  | 300000 | Economica |
| 005     | ingles       | 300000 | Economica |
+---------+--------------+--------+-----------+
5 rows in set (0.00 sec)

MariaDB [fechas001]> exit