Question

我有两个表：

USER_ROLE_TABLE（ID，角色名）

id     role_name
-----------------
  1    Admin
  2    Faculty
  3    Student

USER_TABLE（ID，名称，角色ID）

 id   name    roleid
 -------------------
  1   user1      3
  2   user2      3
  3   user3      1

在注册过程中，我想首先检查具有admin角色的用户是否存在。如果不是，那么我只想在下拉菜单中显示admin选项，否则它将显示所有角色，包括admin。该怎么做？

我只是asp.net的初学者。您的帮助将不胜感激。谢谢

// GET: users/Create
    public ActionResult Create()
    {
        ViewBag.role_id = new SelectList(db.user_role, "id", "role_name");
        return View();
    }

Create.cshtml：

@model Test_drpdown.datamodel.user

@{
ViewBag.Title = "Create";
}
@using (Html.BeginForm()) 
{
@Html.AntiForgeryToken()

<div class="form-horizontal">
    <h4>user</h4>
    <hr />
    @Html.ValidationSummary(true, "", new { @class = "text-danger" })
    <div class="form-group">
        @Html.LabelFor(model => model.name, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.name, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.name, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.role_id, "role_id", htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.DropDownList("role_id", null, htmlAttributes: new { @class = "form-control" })
            @Html.ValidationMessageFor(model => model.role_id, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        <div class="col-md-offset-2 col-md-10">
            <input type="submit" value="Create" class="btn btn-default" />
        </div>
    </div>
</div>
}

如何禁用从数据库检索的下拉项

0 个答案: