Can anyone explain this

Hello,

I'm new in using SQL, but i can't figure why ny example does this :

manip=> select * from mailing ;
file                                           |name                          |display
-----------------------------------------------+------------------------------+-------
https://dooz.corp.intrinsec.com/mail/mail_ed/  |Boite aux lettre du compte Ed |t
https://dooz.corp.intrinsec.com/mail/mail_crs/ |Boite aux lettre du compte Crs|t
https://dooz.corp.intrinsec.com/mail/mail_root/|Boite aux lettre du compte Roo|f
https://dooz.corp.intrinsec.com/mail/mail_other|Boite aux lettre anonyme      |f
https://dooz.corp.intrinsec.com/mail/essai.php3|Recharger cette page          |t
(5 rows)

manip=> insert into mailing values ('a','b',display=true);
INSERT 0 5
manip=> select * from mailing ;
file                                           |name                          |display
-----------------------------------------------+------------------------------+-------
https://dooz.corp.intrinsec.com/mail/mail_ed/  |Boite aux lettre du compte Ed |t
https://dooz.corp.intrinsec.com/mail/mail_crs/ |Boite aux lettre du compte Crs|t
https://dooz.corp.intrinsec.com/mail/mail_root/|Boite aux lettre du compte Roo|f
https://dooz.corp.intrinsec.com/mail/mail_other|Boite aux lettre anonyme      |f
https://dooz.corp.intrinsec.com/mail/essai.php3|Recharger cette page          |t
a                                              |b                             |t
a                                              |b                             |t
a                                              |b                             |f
a                                              |b                             |f
a                                              |b                             |t
(10 rows)

Why does it insert 5 'b', and what would be the correct syntax to insert
only one b
And why values for the attribute display are not always true as i said into
the command ?

--
Edouard DESSIOUX
Proverbe chien :
"Si ca se mange pas,
 Si ca se baise pas,
 Pisse dessus !!"