Question

我在数据库中的表之间有一对多的关系，我想使用API来获取数据。我认为ma.Nested不起作用，因为我没有掌握所有领域有人可以帮我吗？

我只有这个： [ { “ IsRef”：否， “命令”：[ “ 299d7f0b-721c-484b-9448-072716a5fd70”， “ 382c5d9f-99a1-4aa2-ac30-96084e202fad”， “ 299d7f0b-721c-484b-9448-072716a5fd75”， “ 382c5d9f-99a1-4aa2-ac30-96084e202fak” ]， “ filename”：“ uiyg”， “版本”：8 } ]

这是数据库模型：

class File(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    filename = db.Column(db.String(255), unique=True)
    version = db.Column(db.Integer, unique=True)
    IsRef = db.Column(db.Boolean)
    commands = db.relationship('Command', backref='log', lazy='joined')

    def __init__(self, filename, version, IsRef):
        self.filename = filename
        self.version = version
        self.IsRef = IsRef


class Command(db.Model):
    id_command = db.Column(db.String(255), primary_key=True, autoincrement=False)
    name = db.Column(db.String(255))
    log_id = db.Column(db.Integer, db.ForeignKey('file.id'))
    status = db.Column(db.Boolean)
    events = db.relationship('Event', backref='com', lazy='joined')

    def __init__(self, id_command, name, log_id, status):
        self.id_command = id_command
        self.name = name
        self.log = log_id
        self.status = status


class Event(db.Model):
    id_event = db.Column(db.Integer, primary_key=True)
    event_name = db.Column(db.String(255))
    seq_number = db.Column(db.Integer)
    com_id = db.Column(db.Integer, db.ForeignKey('command.id_command'))

    def __init__(self, event_name, seq_number, com_id):
        self.event_name = event_name
        self.seq_number = seq_number
        self.com = com_id

这是架构：


class EventSchema(ma.ModelSchema):
    class Meta:
        model = Event
        fields = ('event_name', 'seq_number')


class CommandSchema(ma.ModelSchema):
    class Meta:
        model = Command
        events = ma.Nested(EventSchema)
        fields = ('id_command', 'name', 'status', 'events')



class LogSchema(ma.ModelSchema):
    class Meta:
        model = File
        commands = ma.Nested(CommandSchema)
        fields = ('filename', 'version', 'IsRef', 'commands')



Log_schema = LogSchema(many=True)

这是API：

@app.route("/getall/<version>", methods=["GET"])
def get_all(version):
    alle = File.query.filter_by(version=version)
    return Log_schema.jsonify(alle)

Answer 1

这个问题解决了。我已将'lazy ='joined'更改为'lazy ='dynamic'，并将ma.Nested排除在Meta类之外

ma.Nested可能无法使用sqlalchemy和棉花糖

1 个答案: