Flask SQLAlchemy 分页错误 [英] Flask SQLAlchemy pagination error

问题描述

我有这个代码和 all() 方法和其他所有方法都适用于此，我已经查看了所有内容，我可以发现 pagination() 方法有效BaseQuery 也是 Query

I have this code and the all() method and every other method works on this and I have looked all over and I could that the method paginate() works on BaseQuery which is also Query

@app.route('/')
@app.route('/index')
@app.route('/blog')
@app.route('/index/<int:page>')
def index(page = 1):
    posts = db.session.query(models.Post).paginate(page, RESULTS_PER_PAGE, False)
return render_template('index.html', title="Home", posts=posts)

但这给了我错误 AttributeError: 'Query' object has no attribute 'paginate'我到处找，但找不到任何解决方案.

but this gives me the error AttributeError: 'Query' object has no attribute 'paginate' I've looked everywhere and I can't find any solution to this.

推荐答案

来自你的问题...

that the method paginate() works on BaseQuery which is also Query

我认为这是您感到困惑的地方.查询"指的是 SQLAlchemy Query 对象.BaseQuery"指的是 Flask-SQLALchemy BaseQuery 对象，它是Query 的子类.这个子类包括诸如 first_or_404() 和 paginate().然而，这意味着 Query 对象没有 paginate() 函数.您实际如何构建您称为查询"对象的对象取决于您是在处理 Query 还是 BaseQuery 对象.

I think this is where you're being confused. "Query" refers to the SQLAlchemy Query object. "BaseQuery" refers to the Flask-SQLALchemy BaseQuery object, which is a subclass of Query. This subclass includes helpers such as first_or_404() and paginate(). However, this means that a Query object does NOT have the paginate() function. How you actually build the object you are calling your "Query" object depends on whether you are dealing with a Query or BaseQuery object.

在这段代码中，你得到了 SQLAlchemy Query 对象，这导致了一个错误:

In this code, you are getting the SQLAlchemy Query object, which results in an error:

db.session.query(models.Post).paginate(...)

如果你使用下面的代码，你会得到你正在寻找的分页，因为你正在处理一个 BaseQuery 对象(来自 Flask-SQLAlchemy)而不是一个 Query 对象(来自 SQLAlchemy).

If you use the following code, you get the pagination you're looking for, because you are dealing with a BaseQuery object (from Flask-SQLAlchemy) rather than a Query object (from SQLAlchemy).

models.Post.query.paginate(...)

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