如何使用flask-sqlalchemy使两个不同表中的两个主键具有唯一性？

from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()

class Table1(db.Model):
    id1 = db.Column(db.Integer, primary_key=True)
    # 其他字段...

class Table2(db.Model):
    id2 = db.Column(db.Integer, primary_key=True)
    # 其他字段...

class Table2(db.Model):
    id2 = db.Column(db.Integer, primary_key=True)
    table1_id = db.Column(db.Integer, db.ForeignKey('table1.id1'))
    # 其他字段...

class Table1(db.Model):
    id1 = db.Column(db.Integer, primary_key=True)
    table2 = db.relationship('Table2', backref='table1')
    # 其他字段...

class Table2(db.Model):
    id2 = db.Column(db.Integer, primary_key=True)
    table1_id = db.Column(db.Integer, db.ForeignKey('table1.id1'))
    # 其他字段...