无法填写mnesia表

Question

我写了这段代码：

Player   = t:user(List),
CatchAll = [{'_', [], ['$_']}],
NameList = mnesia:dirty_select(player, CatchAll),
if
  (length(NameList) < 4)->
    T3 = fun() ->
             X3 = #player{name = Player},
             mnesia:write(X3)
         end,
    mnesia:transaction(T3),
    NameList1 = mnesia:dirty_select(player, CatchAll),
    ?INFO_MSG("1The value of NameList1 is ~p~n", [NameList1]),
    ok;
  (length(NameList) == 4)->
    ?INFO_MSG("2The value of NameList is ~p~n", [NameList])
end,

在这里，每次调用一个模块t：user我得到一个名字，我已经存储在Player中，并希望继续存储这些名称，直到有4个，但每次我运行这个，我得到一个空值名单列为[]，而不是填充玩家名称的列表。

关于为什么会发生这种情况的任何想法？