extract values

[smitha mano]

CREATE TABLE special
(
id serial NOT NULL,
specialname varchar(50),
CONSTRAINT special_pk PRIMARY KEY (id)
)

CREATE TABLE person
(
id serial NOT NULL,
name varchar(60),
qualification varchar(100),
exp int4,
history text,
CONSTRAINT person_pk PRIMARY KEY (id)
)


CREATE TABLE person_spec_group
(
fk_person int4 NOT NULL,
fk_special int4 NOT NULL,
CONSTRAINT person_spec_group FOREIGN KEY (fk_person) REFERENCES person (id) ON UPDATE RESTRICT ON DELETE RESTRICT,
CONSTRAINT special_spec_group FOREIGN KEY (fk_special) REFERENCES special (id) ON UPDATE RESTRICT ON DELETE RESTRICT
)

special table
to store the specialname
person table to store the details of a person
person_spec_group table to store the ids of special table and person table

How to works this or how to write action class and SQL query?