Easy Asterisk Billing

there is basic sql for bill from MySQL CDR:

~~select * from user u, line s, pricelist p where u.iduser=s.iduser and '".$lsrc>'src'."' like s.idmsn and p.acode=s.acode and u.currency=p.currency and right(left('".$dst."',CHAR_LENGTH(p.ccode)+2),CHAR_LENGTH(p.ccode)) like concat(p.ccode,'%') order by p.ccode desc limit 1~~