SQLALchemy-Utils：对LTree使用'〜'运算符(SQLALchemy-Utils: Use '~' operator with LTree)

 我试图使用Flask， SQLAlchemy-Utils和Flask-SQLAlchemy查询Postgres物化路径视图（ltree）。 SQLAlchemy-Util Docs使用LTree显示'=='，'！='运算符的用法。 我怎么能用'〜'运算符？ 
 
 我在sqlalchemy_utils / ltree.py中看到了代码： 
 
class comparator_factory(types.Concatenable.Comparator):
    def ancestor_of(self, other):
        if isinstance(other, list):
            return self.op('@>')(expression.cast(other, ARRAY(LtreeType)))
        else:
            return self.op('@>')(other)

    def descendant_of(self, other):
        if isinstance(other, list):
            return self.op('<@')(expression.cast(other, ARRAY(LtreeType)))
        else:
            return self.op('<@')(other)

    def lquery(self, other):
        if isinstance(other, list):
            return self.op('?')(expression.cast(other, ARRAY(LQUERY)))
        else:
            return self.op('~')(other)

    def ltxtquery(self, other):
        return self.op('@')(other)
 
 这是LtreeType的子类。 
 
 对于一个简单的== ，我正在使用： 
 
Model.query.filter(Model.path == LTree('1.2')).all()
 
 但是使用此表达式会引发验证错误： 
 
Model.query.filter(Model.path == LTree('~1.2')).all()
 
 如何在有效的SQLALchemy查询中格式化上面的表达式？ 

I am trying to query Postgres materialized path view(ltree) using Flask,SQLAlchemy-Utils and Flask-SQLAlchemy. SQLAlchemy-Util Docs shows the usage of '==', '!=' operators using LTree. How can i use '~' operator?
 
I saw the code in sqlalchemy_utils/ltree.py: 
 
class comparator_factory(types.Concatenable.Comparator):
    def ancestor_of(self, other):
        if isinstance(other, list):
            return self.op('@>')(expression.cast(other, ARRAY(LtreeType)))
        else:
            return self.op('@>')(other)

    def descendant_of(self, other):
        if isinstance(other, list):
            return self.op('<@')(expression.cast(other, ARRAY(LtreeType)))
        else:
            return self.op('<@')(other)

    def lquery(self, other):
        if isinstance(other, list):
            return self.op('?')(expression.cast(other, ARRAY(LQUERY)))
        else:
            return self.op('~')(other)

    def ltxtquery(self, other):
        return self.op('@')(other)
 
This is subclass of LtreeType. 
 
For a simple ==, i am using :
 
Model.query.filter(Model.path == LTree('1.2')).all()
 
But using this expression throws validation error:
 
Model.query.filter(Model.path == LTree('~1.2')).all()
 
How can i format above expression in a valid SQLALchemy query?

原文：https://stackoverflow.com/questions/40137655