搜索 Child Objects 没有 Child Objects
Search for Child Objects with No Child Objects
Backendless 文档有一个 example 关于查询相关 objects； 电话簿 (parent) 有 child 联系人 (child) 有 child Address (grandchild) (phonebook->contact->address).
您可以使用 "is null" 到 find parent objects with no child object
Contact is null
但是当你试图找到没有 grandchild objects 的 child objects 时。查询失败 "invalid where clause."
Contact.Address is null
我开发了这个解决方案，它检查孙对象系统生成的字段是否为空。
Contact.Address.created is null //Contact has no Address child object
Contact.Address.created is not null //Contact has Address child object
Backendless 文档有一个 example 关于查询相关 objects； 电话簿 (parent) 有 child 联系人 (child) 有 child Address (grandchild) (phonebook->contact->address).
您可以使用 "is null" 到 find parent objects with no child object
Contact is null
但是当你试图找到没有 grandchild objects 的 child objects 时。查询失败 "invalid where clause."
Contact.Address is null
我开发了这个解决方案，它检查孙对象系统生成的字段是否为空。
Contact.Address.created is null //Contact has no Address child object
Contact.Address.created is not null //Contact has Address child object