Partner Ledger Report using ORM methods in Odoo8 - python-2.7

Question

I am working on partner ledger report and i have prepared report using SQL query
def lines(self, partner):
move_state = ['draft','posted']
if self.target_move == 'posted':
move_state = ['posted']
full_account = []
if self.reconcil:
RECONCILE_TAG = " "
else:
RECONCILE_TAG = "AND l.reconcile_id IS NULL"
self.cr.execute(
"SELECT l.id, l.date, j.code, acc.code as a_code, acc.name as a_name,inv.state,inv.date_due, l.ref, m.name as move_name, l.name, l.debit, l.credit, l.amount_currency,l.currency_id, c.symbol AS currency_code " \
"FROM account_move_line l " \
"LEFT JOIN account_journal j " \
"ON (l.journal_id = j.id) " \
"LEFT JOIN account_account acc " \
"ON (l.account_id = acc.id) " \
"LEFT JOIN res_currency c ON (l.currency_id=c.id)" \
"LEFT JOIN account_move m ON (m.id=l.move_id)" \
"LEFT JOIN account_invoice inv ON (inv.move_id = l.move_id)" \
"WHERE l.partner_id = %s " \
"AND l.account_id IN %s AND " + self.query +" " \
"AND m.state IN %s " \
" " + RECONCILE_TAG + " "\
"ORDER BY l.date",
(partner.id, tuple(self.account_ids), tuple(move_state)))
res = self.cr.dictfetchall()
sum = 0.0
if self.initial_balance:
sum = self.init_bal_sum
for r in res:
sum += r['debit'] - r['credit']
r['progress'] = sum
full_account.append(r)
return full_account
My result are accurate
but now I want to do this using ORM methods and code for this:
account_move_model = self.pool.get('account.move.line')
full_account_custom = []
move_line_ids = account_move_model.search(self.cr, self.uid, [
('partner_id', '=', partner.id), ('account_id', 'in', tuple(self.account_ids)),
('state', 'in', tuple(move_state))
])
move_lines = account_move_model.browse(self.cr, self.uid, move_line_ids)
sum = 0.0
if self.initial_balance:
sum = self.init_bal_sum
for r in move_lines:
sum += r['debit'] - r['credit']
r['progress'] = sum
full_account_custom.append(r)
return full_account_custom
By doing this I am just getting the sum of all invoices of a partner/customer but the list of all invoice is not showing.
Where is the mistake and how to resolve it

Answer 1

Using ORM methods there are some difficulties..
Easy way is to use raw query.