从parse.com空值查询 [英] Queries with empty values from parse.com

问题描述

不知怎的，我无法找到这个问题的答案。

Somehow I couldn't find the answer to this.

我运行一个查询parse.com并希望下载所有包含在我的专栏的一个空值行。

I am running a query to parse.com and want to download all of the rows that contain an empty value in one of my columns.

 ParseQuery<ParseObject> query = ParseQuery.getQuery(Constants.myTestTable);
    query.whereEqualTo("MyColumn", "");

当我上传CSV解析，其中MyColumn没有任何价值的解析显示列单元格（未定义），我不能检索数据。然而，当我删除单元中的所有内容我能找回它。我希望能够以检索数据，如果小区具有默认的（未定义）从解析值。我想...

When I upload a csv to parse where MyColumn does not have any value the column cells on parse show "(undefined)" and I cannot retrieve the data. However, when I delete all content in the cell I am able to retrieve it. I want to be able to retrieve the data if the cell has the default "(undefined)" value from parse. I tried...

ParseQuery<ParseObject> query = ParseQuery.getQuery(Constants.myTestTable);
        query.whereEqualTo("MyColumn", null);

但是，这也不能工作。我敢肯定，有一个简单的解决方案，这一点，我只是不能让党的事情工作。

But that did not work either. I'm sure there is an easy solution to this, I just can't get the dang thing to work.

推荐答案

您想要什么 whereExists 和 whereDoesNotExist

query.whereDoesNotExist("MyColumn");

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