SELECT ID, EMETTEUR, MONTANT, DATE_ENCAISSEMENT, ENCAISSE 
FROM paiements 
WHERE MODE = 'CHQ' 
AND `DATE_ENCAISSEMENT` LIKE '%2011%'
AND i IN (
    SELECT id 
    FROM paiements 
    WHERE date_encaissement 
    LIKE '%2010%' 
    AND encaisse = 1 
    GROUP BY id 
    HAVING COUNT(*) > 0
)