小编cgg*_*cgg的帖子

我正在阅读 Phoenix 1.4 书，当我尝试通过终端将数据输入数据库时​​，我进入“使用存储库数据”部分，但出现错误。

我的 IEx 会话：

iex(1)> alias Rumbl.Repo\nRumbl.Repo\niex(2)> alias Rumbl.Accounts.User\nRumbl.Accounts.User\niex(3)> Repo.insert(%User{\n...(3)> name: "Jos\xc3\xa9", username: "josevalim"\n...(3)> })\n[debug] QUERY ERROR db=16.7ms queue=1.2ms\nINSERT INTO "users" ("name","username","inserted_at","updated_at") VALUES ($1,$2,$3,$4) RETURNING "id" ["Jos\xc3\xa9", "josevalim", ~N[2018-11-24 11:47:30], ~N[2018-11-24 11:47:30]]\n

它引发了以下错误：

** (Ecto.ConstraintError) constraint error when attempting to insert struct:\n\n    * users_username_index (unique_constraint)\n\nIf you would like to stop this constraint violation from raising an\nexception and instead add it as an error to your changeset, please\ncall `unique_constraint/3` on your changeset with the …

int UserA;

Console.WriteLine("What is 5 + 5");
UserA = Convert.ToInt32(Console.ReadLine());
if(UserA == 10) {
    Console.WriteLine("Correct!");
} else if(UserA == 9 || 11 ) {

}

为什么我不能在OR这里使用操作数.我知道它很简单,但我很困惑.