from django.db.models.query import Q, QAnd, QOr

class QLeftOuterJoins(Q):
    "Replaces all INNER JOINs with LEFT OUTER JOINs inside"
    def __init__(self, q):
        self.q = q

    def __and__(self, other):
        return QAnd(self, other)

    def __or__(self, other):
        return QOr(self, other)

    def get_sql(self, opts):
        joins, where, params = self.q.get_sql(opts)
        for join_name, join in joins.iteritems():
            joins[join_name] = (join[0], "LEFT OUTER JOIN", join[2])
        return joins, where, params