java - 在 GQL 过滤器中使用列表

Question

如何使用列表作为过滤器在 GQL 中进行选择。

如果我有课

public class Obj{

    @Persistent
    private Long name;

}

我怎样才能得到名称不在列表中的所有对象？

Answer 1

您可以通过将所有过滤器链接在一起来获得结果。

SELECT * FROM User where email != 'xxx@gmail.com' and email != 'yyy@gmail.com' and email != 'zzz@gmail.com'

Python代码

q = User.all()
for i in ilist:
    q = q.filter("email = ", i)

但是您可能需要知道这种查询有一些限制。

Note: The IN and != operators use multiple queries behind the scenes. For example, the IN operator executes a separate underlying datastore query for every item in the list. The entities returned are a result of the cross-product of all the underlying datastore queries and are de-duplicated. A maximum of 30 datastore queries are allowed for any single GQL query.