Question

我是新开发人员，我尝试在flask中创建小型应用程序-sqlalchemy和flask_admin。这是我的模特：

class Language(db.Model):
    __tablename__ = "languages"
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(length=50), nullable=False)

class Article(db.Model):
    __tablename__ = 'articles'
    from_language_id = db.Column(db.Integer, db.ForeignKey('languages.id'), nullable=True)
    to_language_id = db.Column(db.Integer, db.ForeignKey('languages.id'), nullable=True)
    language_from = db.relationship('Language', backref='article_language_from')
    language_to = db.relationship('Language', backref='article_language_to')

模型让我看到这个错误：

sqlalchemy.exc.AmbiguousForeignKeysError：无法确定联接父/子表之间的关系条件 article.language_from-有多个外键路径链接桌子。指定“ foreign_keys”参数，并提供那些应该算作包含外键的列引用父表。

我想两次在模型文章中使用模型语言from_language_id和to_language_id，我该如何解决我的错误？

编辑：我的错误，错误来自flask_admin ==> https://pastebin.com/R2E2zp18，我该如何解决？

Answer 1

尝试一下：

class Language(db.Model):
    __tablename__ = "languages"
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(length=50), nullable=False)

class Article(db.Model):
    __tablename__ = 'articles'
    id = db.Column(db.Integer, primary_key=True)
    from_language_id = db.Column(db.Integer, db.ForeignKey('languages.id'), nullable=True)
    to_language_id = db.Column(db.Integer, db.ForeignKey('languages.id'), nullable=True)
    language_from = db.relationship('Language', backref='article_language_from')
    language_to = db.relationship('Language', backref='article_language_to')

输出：

test=# \d articles
                                 Table "public.articles"
      Column      |  Type   | Collation | Nullable |               Default                
------------------+---------+-----------+----------+--------------------------------------
 id               | integer |           | not null | nextval('articles_id_seq'::regclass)
 from_language_id | integer |           |          | 
 to_language_id   | integer |           |          | 
Indexes:
    "articles_pkey" PRIMARY KEY, btree (id)
Foreign-key constraints:
    "articles_from_language_id_fkey" FOREIGN KEY (from_language_id) REFERENCES languages(id)
    "articles_to_language_id_fkey" FOREIGN KEY (to_language_id) REFERENCES languages(id)

test=# \d languages;
                                   Table "public.languages"
 Column |         Type          | Collation | Nullable |                Default                
--------+-----------------------+-----------+----------+---------------------------------------
 id     | integer               |           | not null | nextval('languages_id_seq'::regclass)
 name   | character varying(50) |           | not null | 
Indexes:
    "languages_pkey" PRIMARY KEY, btree (id)
Referenced by:
    TABLE "articles" CONSTRAINT "articles_from_language_id_fkey" FOREIGN KEY (from_language_id) REFERENCES languages(id)
    TABLE "articles" CONSTRAINT "articles_to_language_id_fkey" FOREIGN KEY (to_language_id) REFERENCES languages(id)

Answer 2

您好，我只是复制了您的代码并在Article类中添加了ID，here可以正常工作

烧瓶sqlalchemy：sqlalchemy.exc.AmbiguousForeignKeysError

2 个答案: