因此,我尝试首次尝试使用Realm Database。我正在尝试在数据库中建立关系。
这是JSON
{
"id": 1,
"name": "Definizioni generali - Doveri nell'uso della strada",
"image": "559",
"video": "0",
"created_at": "2019-03-14 22:27:23",
"updated_at": "2019-03-14 22:27:23",
"sections": [
{
"id": 3110,
"chapter_id": 1,
"name": "a) Definizioni stradali e di traffico",
"created_at": "2019-03-14 22:30:52",
"updated_at": "2019-03-14 22:30:52"
},
{
"id": 3123,
"chapter_id": 1,
"name": "b) Definizioni e classificazione dei veicoli",
"created_at": "2019-03-14 22:30:52",
"updated_at": "2019-03-14 22:30:52"
},
{
"id": 3131,
"chapter_id": 1,
"name": "c) Doveri del conducente nell'uso della strada - Convivenza civile e uso responsabile della strada",
"created_at": "2019-03-14 22:30:52",
"updated_at": "2019-03-14 22:30:52"
},
{
"id": 3137,
"chapter_id": 1,
"name": "d) Riguardo verso gli utenti deboli della strada",
"created_at": "2019-03-14 22:30:52",
"updated_at": "2019-03-14 22:30:52"
}
]
}
这是我的章节课
class Chapter: Object, Mappable {
@objc dynamic var id:Int = -1
@objc dynamic var name: String = kBlankString
@objc dynamic var image: String = kBlankString
@objc dynamic var video: String = kBlankString
@objc dynamic var createdAt: String = kBlankString
@objc dynamic var updatedAt: String = kBlankString
var sections = List<Section>()
override static func primaryKey() -> String? {
return "id"
}
required convenience init?(map: Map) {
self.init()
}
func mapping(map: Map) {
id <- map["id"]
name <- map["name"]
image <- map["image"]
video <- map["video"]
createdAt <- map["created_at"]
updatedAt <- map["updated_at"]
sections <- map["sections"]
}
}
在此行上sections <- map["sections"]
我添加了一个断点并检查了po map["sections"].JSON
它在此处显示数据。
问题在于,章节存储在数据库中,但是每章的部分列表为空,而不是为
这是部分类:
class Section: Object, Mappable {
@objc dynamic var id: Int = -1
@objc dynamic var chapterID: Int = -1
@objc dynamic var name: String = kBlankString
@objc dynamic var createdAt: String = kBlankString
@objc dynamic var updatedAt: String = kBlankString
override static func primaryKey() -> String? {
return "id"
}
required convenience init?(map: Map) {
self.init()
}
func mapping(map: Map) {
id <- map["id"]
chapterID <- map["chapter_id"]
name <- map["name"]
createdAt <- map["created_at"]
updatedAt <- map["updated_at"]
}
}
如果我做不正确的事情,请指导我,这是我对领域数据库的第一次尝试。谢谢
首先,我认为这是使用ObjectMapper(https://github.com/tristanhimmelman/objectmmapper),我我自己没有使用过。
,但是问题是您要为各节所做的地图会给您一个数组类型(如我所知),但是领域不支持数组(如您所知,正如您正确使用的那样List
)。
我认为您需要一个自定义转换(https://github.com/tristanhimmelman/objectmmapper#custom-transforms)来转换为List<>
类型。领域显示了如何做到这一点。这显示了在示例代码中完成您想要的等效行 - 重要的位是该行(翻译为使用您的类型):
sections <- (map["sections"], ListTransform<Section>())