CoreData - 将实体的属性设置为非null - 属性应设置为Optional或Mandatory [英] CoreData - Setting a property of entity to be not null - Should the attribute be set as Optional or Mandatory

问题描述

我需要将Coredata的实体中的属性设置为不为null并具有默认值。

I need to have an attribute in Coredata's entity be set as not null and have a default value.

我已为实体的属性设置了默认值在.xcdatamodeld模式定义

I have set a default value for the attribute of the Entity in the .xcdatamodeld schema definition

我的问题是属性是否被标记为可选。

My question is Should the attribute be marked as Optional or not.

将会影响如果我不检查以下三个属性的任何一个 - 瞬态，可选，索引？

What will be the impact if I don't check any of the following three to the attribute - Transient, Optional, Indexed ? Will this attribute be treated as mandatory ?

编辑：当我将属性设置为强制性，如果尝试设置的值为nil，则插入失败，错误代码为1570 - NSValidationMissingMandatoryPropertyError，其中我只是期望属性设置其默认值并插入。

When I set the property as mandatory and if the value trying to set is nil, the insert fails with error code 1570 - NSValidationMissingMandatoryPropertyError, where I am simply expecting the property to be set its default value and gets inserted.

具有默认值的意义是什么？任何人都可以帮助我这里真正缺少的。

What is the point of having a default value then ? Can anyone help me what I am really missing here.

推荐答案

设置为强制性并配置一个适当的默认值 0 ）。如果是可选的，则不保证默认值的设置，而不考虑其他选项。

Set it as mandatory and configure it with an appropriate default value (e.g. 0). If it is optional, the setting of the default value is not guaranteed, regardless of the other options.

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