Python 3.x 明确规定；从「；桌子_Python 3.x_Sqlalchemy

Python 3.x 明确规定；从「；桌子

python-3.x sqlalchemy

Python 3.x 明确规定；从「；桌子,python-3.x,sqlalchemy,Python 3.x,Sqlalchemy,我目前有以下疑问： query = self.session.query(Student, School).join( Person.student, aliased=True).join( Student.school, aliased=True).filter( Person.id == 1) 它编译成这个SQL SELECT student.id AS student_id, student.school_id AS student_school_id, stud

我目前有以下疑问：

query = self.session.query(Student, School).join(
    Person.student, aliased=True).join(
    Student.school, aliased=True).filter(
    Person.id == 1)

它编译成这个SQL

SELECT student.id AS student_id, student.school_id AS student_school_id, student.person_id AS student_person_id, school.id AS school_id, school.name AS school_name 
FROM student, school, person JOIN student AS student_1 ON person.id = student_1.person_id JOIN school AS school_1 ON school_1.id = student_1.school_id 
WHERE person.id = :id_1

我希望查询保持原样，但我希望from语句完全来自

Person

模型。大概是

SELECT * FROM person JOIN ... WHERE person.id = :id_1

我认为带别名的kwarg把情况搞砸了。删除带别名的kwarg可以修复该行为，但我需要带别名的kwarg用于特殊用例。如何从“from”语句中删除

student

和

school

表。

到

的aliased
参数。join

使用匿名别名，这意味着传递到

会话的student
和school
表。query

是表的不同“实例”

from sqlalchemy.orm import aliased

aliased_student = aliased(Student)
aliased_school = aliased(School)

query = (
    session.query(aliased_student, aliased_school)
    .select_from(Person)
    .join(aliased_student, Person.student)
    .join(aliased_school, Student.school)
    .filter(Person.id == 1))

在这里您可以看到，您可以告诉

.join

在加入关系时使用哪个别名。

加入

的别名
参数使用匿名别名，这意味着传递给会话的学生
和学校
。查询
是表的不同“实例”
from sqlalchemy.orm import aliased

aliased_student = aliased(Student)
aliased_school = aliased(School)

query = (
    session.query(aliased_student, aliased_school)
    .select_from(Person)
    .join(aliased_student, Person.student)
    .join(aliased_school, Student.school)
    .filter(Person.id == 1))

在这里您可以看到，您可以告诉.join
在加入关系时要使用哪个别名