我有以下SQL查询：

SELECT messages1.id, messages1.channel FROM (SELECT * FROM messages WHERE timestamp >= datetime.now() AND channel IN ('ALL', 'UC')) messages1 LEFT JOIN read_messages ON messages1.id = read_messages.message_id WHERE read_messages.id IS NULL;

这些是我的模特

from django.db import models

class Messages(models.Model):
    channel = models.TextField(blank=True, null=True)
    message = models.TextField(blank=True, null=True)
    timestamp = models.TextField(blank=True, null=True)
    publisher = models.IntegerField(blank=True, null=True)
    type = models.CharField(max_length=5)

    class Meta:
        managed = False
        db_table = 'messages'

class NotifiedMessages(models.Model):
    id = models.IntegerField(primary_key=True)
    user_id = models.IntegerField()
    message_id = models.IntegerField()

    class Meta:
        managed = False
        db_table = 'notified_messages'

class ReadMessages(models.Model):
    user_id = models.IntegerField(blank=True, null=True)
    message_id = models.IntegerField(blank=True, null=True)

    class Meta:
        managed = False
        db_table = 'read_messages'

我已经尝试使用子查询和其他东西，但现在的主要问题是子查询返回错误：django.db.utils.ProgrammingError: subquery must return only one column
因为我想做这样的事

ts = Messages.objects.filter(timestamp__gte=datetime.today(), channel__in=['ALL', 'UC'])
Messages.objects.annotate(messages1=Subquery(ts, output_field=models.CharField()))

上面的代码有什么问题？2我该怎么做才能正确地翻译查询？