Question

我正在尝试编写一个查询，可以使用aggregate函数找到最多行数。但是，当我尝试运行代码

时，我收到错误

以下是我的示例代码

<dom-module id="demo-admin">
  <template>
    <app-route
      route="{{route}}"
      pattern="/:category"
      data="{{routeData}}"
      tail="{{subroute}}">
    </app-route>

    <h1>Admin</h1>

    <ul>
      <li><a href="/admin/users">Users</a></li>
      <li><a href="/admin/bars">Bars</a></li>
      <li><a href="/admin/stepsheets">Stepsheets</a></li>
      <li><a href="/admin/events">Events</a></li>
    </ul>

    <p>subroute: [[subroute]]</p>

    <iron-pages
      role="main"selected="[[category]]" attr-for-selected="name" selected-attribute="visible" fallback-selection="404">
      <demo-list name="list" route="{{subroute}}"></demo-list>
      <!-- Other pages -->
    </iron-pages>
  </template>
  <script>
    class DemoAdmin extends Polymer.Element {

      static get is() {
        return "demo-admin";
      }

      static get properties() {
        return {
          category: {
            type: String,
            reflectToAttribute: true,
            observer: '_categoryChanged',
          },
          routeData: Object,
          subroute: Object,
        };
      }

      static get observers() {
        return [
          '_routeCategoryChanged(routeData.category)',
        ];
      }

      _routeCategoryChanged(page) {
        this.page = page || 'defaultPage';
      }

      _categoryChanged(page) {
        const resolvedPageUrl = this.resolveUrl('demo-' + page + '.html');
        Polymer.importHref(
          resolvedPageUrl,
          null,
          this._showPage404.bind(this),
          true);
      }

      _showPage404() {
        this.page = '404';
      }

    }
    customElements.define(DemoAdmin.is, DemoAdmin);
  </script>
</dom-module>

运行代码时出现此错误

app-route

请帮忙看看，看看有什么不对，谢谢

Answer 1

未来[[人]] - 我想这应该是未来[人]。

Answer 2

我后来试过这个并且有效

def agg (): Future[Option[Int]]  = db.run {
    people.map(_.age).max.result
  }

在播放浮动时无法进行聚合查询

2 个答案: