Impossible d'effectuer la requête

Voici la requête :
SELECT tb_description, tb_nom, tb_id, tb_tpl, tb_css, tb_page, tb_votes, tb_comments, tb_ext_add, tb_fiche, tb_nbcol, tb_active FROM an_tables WHERE tb_id=

Voici le message d'erreur renvoyé par la base de données :
1064 : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1
Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /home/marocvoy/public_html/annuaire.php on line 62
Fatal error Impossible d'effectuer la requête

Voici la requête :
SELECT inf_id, inf_nom, inf_titre,inf_type, inf_required, inf_tri, inf_search, inf_title FROM an_infos WHERE tb_id=

Voici le message d'erreur renvoyé par la base de données :
1064 : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1
Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /home/marocvoy/public_html/annuaire.php on line 198
Impossible d'effectuer la requête

Voici la requête :
SELECT count(*) as qte FROM an_enr WHERE tb_id= AND enr_valid="O"

Voici le message d'erreur renvoyé par la base de données :
1064 : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'AND enr_valid="O"' at line 1
Warning: Division by zero in /home/marocvoy/public_html/annuaire.php on line 404
Impossible d'effectuer la requête

Voici la requête :
SELECT enr_id FROM an_enr WHERE an_enr.tb_id= AND enr_valid="O" ORDER BY enr_partner DESC, enr_date DESC, enr_id desc LIMIT 0,

Voici le message d'erreur renvoyé par la base de données :
1064 : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'AND enr_valid="O" ORDER BY enr_partner DESC, enr_date DESC, enr_id desc LIMIT' at line 1
Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /home/marocvoy/public_html/annuaire.php on line 474