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javagoogle-app-enginegqlgqlquery

Using List in GQL Filter

How can I make a selection in GQL using a List as filter.

If I have the class

public class Obj{

    @Persistent
    private Long name;

}

How can I get all Obj's that the name are not in a list?

Solution

  • You can get the results by chain all filters together.

    SELECT * FROM User where email != '[email protected]' and email != '[email protected]' and email != '[email protected]'

    Python Code

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

    But you may need to know there are some limitations for this kind of query.

    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.