SELECT
rdb$get_context('USER_TRANSACTION', 'row#') AS codaod,

aod.codaos,
aod.documento,
aod.valor,

rdb$set_context('USER_TRANSACTION', 'row#', COALESCE(CAST(rdb$get_context('USER_TRANSACTION', 'row#') AS INTEGER), 0) + 1)

FROM
    apontamentosos_documentos aod
ORDER BY
    aod.codaos,
    aod.documento