Peewee query - TypeError: '>' not supported between instances of 'ModelCompoundSelectQuery' and 'int'

Question

在 Peewee 3.7.0 中，执行以下代码时出现此错误：

TypeError: '>' not supported between instances of 'ModelCompoundSelectQuery' and 'int'

def myMethod(lastItemDbId):
  # lastItemDbId is an int
  ...

  columnX = fn.Lower(People.name)

  lastItemColumnX = People.select(columnX).where(People.id == lastItemDbId)

  results = People.select(People.id).where(People.parent.is_null() & (columnX > lastItemColumnX | (columnX == lastItemColumnX & People.id > lastItemDbId))).order_by(columnX, People.id).limit(limit)

问题似乎出在 People.id > lastItemDbId 部分，但我不明白为什么。删除 People.id > lastItemDbId 部分，错误消失......但单独测试该部分也有效（见下文）

results = People.select(People.id).where(People.id > lastItemDbId).order_by(columnX, People.id).limit(limit)

如果您想知道，这是 Peewee 模型定义：

class People(Model):
    name = CharField()
    parent = ForeignKeyField('self', backref='children', null=True, on_delete='CASCADE')

Answer 1

来自 Peewee 文档：

Note that the actual comparisons are wrapped in parentheses. Python’s operator precedence necessitates that comparisons be wrapped in parentheses.

即使明显多余，解决方案是将在“&”和“|”等按位运算符左侧和右侧找到的每个逻辑部分括在括号中。

所以解决方案是：

results = People.select(People.id).where((People.parent.is_null()) & ((columnX > lastItemColumnX) | ((columnX == lastItemColumnX) & (People.id > lastItemDbId)))).order_by(columnX, People.id).limit(limit)

Peewee query - TypeError: '>' not supported between instances of 'ModelCompoundSelectQuery' and 'int'

Peewee query - TypeError: '>' not supported between instances of 'ModelCompoundSelectQuery' and 'int'

python-3.x

sqlite

peewee