如何使用golang更新Firestore中的数组元素？

Question

Following code:

Lobby := map[string]interface{}{
        "table_id"          :"new table id",
        "Status"            : true,
        "name"              : "shivam",
        "array":[]interface{}{0,1,3},// this replace existing array with new values
    }

result, err := client.Collection("lobbies").Doc("12").Set(ctx,Lobby,firestore.MergeAll)

I just want to update 2nd element in array with the new value

Answer 1

There is no way to inform a database to replace a specific element in a slice or array.

Your array field stores a slice and is not a map, so you need to implement your own code that will regenerate that slice in the way you need and replace it in the document, something like:

Lobby := map[string]interface{} {
    "table_id" : "new table id",
    "Status"   : true,
    "name"     : "shivam",
    "array"    : []interface{}{0,1,3},
}

new_slice, err := change_my_slice(Lobby["array"])
if err != nil {
    log.Errorf("Error message goes here")
    return nil, err
}
Lobby["array"] = new_slice

result, err := client.Collection("lobbies").Doc("12").Set(ctx,Lobby,firestore.MergeAll)