DB escuela

insert into alumnos values (1, 'jorge','carvalho', 23);

insert into alumnos values (2,'lucas', 'vargas',27);

insert into alumnos values (3, 'gonzalo','cardoso',30);

insert into alumnos values (4 , 'gonzalo','pesado',22);

insert into alumnos values (5, 'maxi','correa',23);

insert into alumnos values (6, 'maxi', 'contetas',22);

insert into materias values (1,'base de datos');

insert into materias values (2,'programacion ');

insert into materias values (3,'organizacion');

insert into materias values (4 ,'matematica');

insert into materias values (5 ,'psec');

insert into cursa values (1,1,'2018-03-04');

insert into cursa values (2,5,'2017-03-04');

insert into cursa values (3,4,'2017-06-01');

insert into cursa values (1,5,'2016-03-05');

insert into cursa values (1,2'2018-03-10');

insert into cursa values (5,3,'2018-03-04');