MariaDB [(none)]> create database seguridad;
Query OK, 1 row affected (0.035 sec)

MariaDB [(none)]> use seguridad;
Database changed
MariaDB [seguridad]> creatr table usuario
    -> (Nombre varchar(20) not null,
    -> Clave varcha(10) null);
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 'creatr table usuario
(Nombre varchar(20) not null,
Clave varcha(10) null)' at line 1
MariaDB [seguridad]> creatr table usuario
    -> creatr table usuario
    -> 
    -> );
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 'creatr table usuario
creatr table usuario

)' at line 1
MariaDB [seguridad]> create table usuario
    -> (Nombre varchar(20) not null,
    -> Clave varchar(10) null);
Query OK, 0 rows affected (0.099 sec)

MariaDB [seguridad]> describe usuario;
+--------+-------------+------+-----+---------+-------+
| Field  | Type        | Null | Key | Default | Extra |
+--------+-------------+------+-----+---------+-------+
| Nombre | varchar(20) | NO   |     | NULL    |       |
| Clave  | varchar(10) | YES  |     | NULL    |       |
+--------+-------------+------+-----+---------+-------+
2 rows in set (0.089 sec)

MariaDB [seguridad]> insert into usuario value('Mauricio Sepulveda',encode('mao','78890));
    '> insert into usuario value('Mauricio Sepulveda',encode('mao','78890'));
    '> '
    -> ;
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 'Sepulveda',encode('mao','78890'));
'' at line 1
MariaDB [seguridad]> insert into usuario value('Mauricio Sepulveda',encode('mao','78890'));
Query OK, 1 row affected, 1 warning (0.213 sec)

MariaDB [seguridad]> select* from usuario;
+--------------------+-------+
| Nombre             | Clave |
+--------------------+-------+
| Mauricio Sepulveda | ?)
   |
+--------------------+-------+
1 row in set (0.001 sec)

MariaDB [seguridad]> insert into usuario value('Javier Ospina Moreno',encode('jom','456'));
Query OK, 1 row affected (0.004 sec)

MariaDB [seguridad]> insert into usuario value('Gustavo Lopera',encode('gus','1234'));
Query OK, 1 row affected (0.004 sec)

MariaDB [seguridad]> insert into usuario value('Christian Camilo Trespalacios',encode('cct','1601'));
Query OK, 1 row affected, 1 warning (0.004 sec)

MariaDB [seguridad]> select* from usuario;
+----------------------+-------+
| Nombre               | Clave |
+----------------------+-------+
| Mauricio Sepulveda   | ?)
   |
| Javier Ospina Moreno | }}   |
| Gustavo Lopera       | *\   |
| Christian Camilo Tre | "^   |
+----------------------+-------+
4 rows in set (0.001 sec)

MariaDB [seguridad]> insert into usuario value('Christian Camilo Palacios',encode('cct','1601'));
Query OK, 1 row affected, 1 warning (0.004 sec)

MariaDB [seguridad]> select* from usuario;
+----------------------+-------+
| Nombre               | Clave |
+----------------------+-------+
| Mauricio Sepulveda   | ?)
   |
| Javier Ospina Moreno | }}   |
| Gustavo Lopera       | *\   |
| Christian Camilo Tre | "^   |
| Christian Camilo Pal | "^   |
+----------------------+-------+
5 rows in set (0.001 sec)

MariaDB [seguridad]> select decode(clave,'7889') from usuario where nombre='Mauricio Sepulveda';
+----------------------+
| decode(clave,'7889') |
+----------------------+
| ?q?                  |
+----------------------+
1 row in set (0.002 sec)

MariaDB [seguridad]> select decode(clave,'7889') from usuario where nombre='Mauricio Sepulveda';
+----------------------+
| decode(clave,'7889') |
+----------------------+
| ?q?                  |
+----------------------+
1 row in set (0.001 sec)

MariaDB [seguridad]> select decode(clave,'78890') from usuario where nombre='Mauricio Sepulveda';
+-----------------------+
| decode(clave,'78890') |
+-----------------------+
| (-                    |
+-----------------------+
1 row in set (0.001 sec)

MariaDB [seguridad]> insert into usuario value('Camilo Palacios',encode('cctp','0816'));
Query OK, 1 row affected, 1 warning (0.009 sec)

MariaDB [seguridad]> select decode(clave,'0816') from usuario where nombre='Camilo Palacios';
+----------------------+
| decode(clave,'0816') |
+----------------------+
| cct?                 |
+----------------------+
1 row in set (0.001 sec)

MariaDB [seguridad]> select decode(clave,'1234') from usuario where nombre='Gustavo Lopera';
+----------------------+
| decode(clave,'1234') |
+----------------------+
| gus                  |
+----------------------+
1 row in set (0.001 sec)

MariaDB [seguridad]> select locate('r','sergio se rie mucho');
+-----------------------------------+
| locate('r','sergio se rie mucho') |
+-----------------------------------+
|                                 3 |
+-----------------------------------+
1 row in set (0.019 sec)

MariaDB [seguridad]> select decode(clave,'78890') from usuario where nombre='Mauricio Sepulveda';
+-----------------------+
| decode(clave,'78890') |
+-----------------------+
| (-                    |
+-----------------------+
1 row in set (0.001 sec)

MariaDB [seguridad]> select locate('r','sergio se rie mucho');
+-----------------------------------+
| locate('r','sergio se rie mucho') |
+-----------------------------------+
|                                 3 |
+-----------------------------------+
1 row in set (0.001 sec)

MariaDB [seguridad]> select locate('s','sergio se rie mucho');
+-----------------------------------+
| locate('s','sergio se rie mucho') |
+-----------------------------------+
|                                 1 |
+-----------------------------------+
1 row in set (0.001 sec)

MariaDB [seguridad]> select locate('i','sergio se rie mucho');
+-----------------------------------+
| locate('i','sergio se rie mucho') |
+-----------------------------------+
|                                 5 |
+-----------------------------------+
1 row in set (0.001 sec)

MariaDB [seguridad]> select position('i' in 'sergio se rie mucho');
+----------------------------------------+
| position('i' in 'sergio se rie mucho') |
+----------------------------------------+
|                                      5 |
+----------------------------------------+
1 row in set (0.021 sec)

MariaDB [seguridad]> select mid('hola como estas' from 4  for 6);
+--------------------------------------+
| mid('hola como estas' from 4  for 6) |
+--------------------------------------+
| a como                               |
+--------------------------------------+
1 row in set (0.033 sec)

MariaDB [seguridad]> select ltrim('     estudien chicos     ');
+------------------------------------+
| ltrim('     estudien chicos     ') |
+------------------------------------+
| estudien chicos                    |
+------------------------------------+
1 row in set (0.002 sec)

MariaDB [seguridad]> select rtrim('     estudien chicos     ');
+------------------------------------+
| rtrim('     estudien chicos     ') |
+------------------------------------+
|      estudien chicos               |
+------------------------------------+
1 row in set (0.001 sec)

MariaDB [seguridad]> select trim('     estudien chicos     ');
+-----------------------------------+
| trim('     estudien chicos     ') |
+-----------------------------------+
| estudien chicos                   |
+-----------------------------------+
1 row in set (0.001 sec)

MariaDB [seguridad]> [17:16] Javier Ospina Moreno
    -> select trim(leading '0' from '00estudien chicos00');
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 '[17:16] Javier Ospina Moreno
select trim(leading '0' from '00estudien chicos00')' at line 1
MariaDB [seguridad]> 
MariaDB [seguridad]> [17:16] Javier Ospina Moreno
    -> select trim(leading '0' from '00estudien chicos00');
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 '[17:16] Javier Ospina Moreno
select trim(leading '0' from '00estudien chicos00')' at line 1
MariaDB [seguridad]> 
MariaDB [seguridad]> select trim(leading '0' from '00estudien chicos00');
+----------------------------------------------+
| trim(leading '0' from '00estudien chicos00') |
+----------------------------------------------+
| estudien chicos00                            |
+----------------------------------------------+
1 row in set (0.002 sec)

MariaDB [seguridad]> select trim(trailing '0' from '00estudien chicos00');
+-----------------------------------------------+
| trim(trailing '0' from '00estudien chicos00') |
+-----------------------------------------------+
| 00estudien chicos                             |
+-----------------------------------------------+
1 row in set (0.001 sec)

MariaDB [seguridad]> select trim(both '0' from '00estudien chicos00');
+-------------------------------------------+
| trim(both '0' from '00estudien chicos00') |
+-------------------------------------------+
| estudien chicos                           |
+-------------------------------------------+
1 row in set (0.000 sec)

MariaDB [seguridad]> exit