英文:
golang can't reflect to map[interface{}]interface{}
问题
我的原始问题是，我想将URL.Values解析为通用类型（map[interface{}]interface{}），然后编辑/添加一些值，然后将其转换为JSON字符串并放入PostgreSQL的JSON列中。
我尝试使用以下代码进行解析，但是content似乎为空，而err为false。request.URL.Query()打印了一个很好的map对象。
v := reflect.ValueOf(request.URL.Query())
i := v.Interface()
content, err := i.(map[interface{}]interface{})
// 进行一些操作
jsonString, _ := json.Marshal(content)
// 添加到数据库
为什么它为空？我想得太泛化了吗？
英文:
My original problem is I want to parse URL.Values to a generic type (map[interface{}]interface{}) edit/add some values then convert it to JSON string and put it to PostgreSQL JSON column.
I tried this code to parse it but content seems to be null whereas err is false. request.URL.Query() prints a nice map object.
v := reflect.ValueOf(request.URL.Query())
i := v.Interface()
content, err := i.(map[interface{}]interface{})
// Do some operations
jsonString, _ := json.Marshal(content)
// Add to DB
Why is it null? Also am I thinking too generic?
答案1
得分: 3
content, err := i.(map[interface{}]interface{})，这不是一个类型转换，而是一个类型断言。你在断言接口的类型是map[interface{}]interface{}，但实际上它的类型是map[string][]string。你得到的值是null，是因为断言失败了。我非常怀疑error是false。
你是不是想得太泛化了？当然是的。我想不出为什么集合类型需要改变的任何理由...你可以向其中添加任何内容，将其写入数据库。据我所知，没有任何限制。
英文:
content, err := i.(map[interface{}]interface{}), this isn't a cast, it's a type assertion. You're saying (asserting) that interface is of type map[interface{}]interface{}, it's not. It's of type map[string][]string. You get null as the value because it fails. I highly doubt error is false.
Are you thinking too generic? Of course you are. I can't think of any reason why the collections type needs to change... Append what you want to it, write it to your db. There's nothing preventing that afaik?
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