'Search the channel database for a particular channel.
Args:
ostring (str): The key or database id of the channel.
exact (bool, optional): Require an exact (but not
case sensitive) match.'

@returns_typeclass_list
def search_channel(self, ostring, exact=True):

    channels = []
    if (not ostring):
        return channels
    try:
        dbref = int(ostring.strip('#'))
        channels = self.filter(id=dbref)
    except Exception:
        pass
    if (not channels):
        if exact:
            channels = self.filter(db_key__iexact=ostring)
        else:
            channels = self.filter(db_key__icontains=ostring)
    if (not channels):
        channels = [channel for channel in self.all() if (ostring.lower() in [a.lower for a in channel.aliases.all()])]
    return channels
