google-app-engine - Go 中使用 GAE 数据存储时，指向 slice 的指针 "relationships"是否正常？

Question

根据Ancestor Queries从 App Engine 文档中，我可以执行以下操作:

type Team struct {
    Name string
}

type Player struct {
    Name string
}

// Save data first just for the test case
teamA := datastore.NewIncompleteKey(c, "Team", nil)
teamA, _ = datastore.Put(c, teamA, Team{"Team A"})
playerA := datastore.NewIncompleteKey(c, "Player", teamA)
playerA, _ = datastore.Put(c, playerA, Player{"Player A"})
playerB := datastore.NewIncompleteKey(c, "Player", teamA)
playerB , _ = datastore.Put(c, playerB, Player{"Player B"})

// query data
q := datastore.NewQuery("Team").Filter("Name=", "Team A").Limit(1).KeysOnly()
teams, _ := q.GetAll(c, nil)
q = datastore.NewQuery("Player").Ancestor(teams[0])
var players []Player
q.GetAll(c, &players)

但是...如果我想让 Team 包含一个指向玩家 slice 的指针，那么我会将其保存为 nil，当我查询它时，我会分配它，有点像这样:

type Team struct {
    Name string
    Players *[]Player `datastore:-`
}

type Player {
    Name string
}

// Save data first just for the test case
teamA := datastore.NewIncompleteKey(c, "Team", nil)
teamA, _ = datastore.Put(c, teamA, Team{"Team A", nil})

/* Saving player data goes here */

// query data
q := datastore.NewQuery("Team").Filter("Name=", "Team A").Limit(1)
var teams []Team
teamKeys, _ := q.GetAll(c, teams)
q = datastore.NewQuery("Player").Ancestor(teamKeys[0])
q.GetAll(c, teams[0].Players)

这是模拟关系的好方法吗？
对于我的应用程序，树结构将是完美适合我手指的戒指。
或者也许...您还有其他建议吗？

Answer 1

我认为指针不是数据存储的有效类型!
从这里:https://developers.google.com/appengine/docs/go/datastore/reference

An entity's contents are a mapping from case-sensitive field names to values. Valid value types are:

- signed integers (int, int8, int16, int32 and int64),
- bool,
- string,
- float32 and float64,
- any type whose underlying type is one of the above predeclared types,
- *Key,
- time.Time,
- appengine.BlobKey,
- []byte (up to 1 megabyte in length),
- structs whose fields are all valid value types,
- slices of any of the above.

或者也许...您还有其他建议吗？
播放器 slice 可能有效(未经测试)
或者也许您应该搜索 "The PropertyLoadSaver Interface"在同一个 URL 中。这就像您选择将内容插入到数据存储中的内容和方式，而不是让它自动插入。