Firebase:扑扑想要获取空值 [英] Firebase: flutter want to get a null value

问题描述

我想在Firebase数据库中获取空数据

I want to get data that is null in a Firebase database

stream: Firestore.instance
      .collection('resep')
      .where("email", isEqualTo: null)
      .snapshots(),

我想获取为空的电子邮件数据

I want to get email data that is null

推荐答案

来自文档:

where(dynamic field，{dynamic isEqualTo，dynamic isLessThan，dynamicisLessThanOrEqualTo，动态isGreaterThan，动态isGreaterThanOrEqualTo，动态arrayContains，bool isNull})→查询创建并返回带有指定的附加过滤器的新查询场地.字段是指文档中的字段.[...]

where(dynamic field, { dynamic isEqualTo, dynamic isLessThan, dynamic isLessThanOrEqualTo, dynamic isGreaterThan, dynamic isGreaterThanOrEqualTo, dynamic arrayContains, bool isNull }) → Query Creates and returns a new Query with additional filter on specified field. field refers to a field in a document. [...]

有一个isNull属性

There is a isNull property

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