修复CURD代码生成的关联报错

app/admin/library/traits/Backend.php

@@ -301,7 +301,40 @@ trait Backend
     /**
      * 加载为 select(远程下拉选择框)数据，子类可覆盖
      */
-    protected function _select(): void
+    protected function _select(): Response
     {
+        if (empty($this->model)) {
+            return $this->success('', [
+                'list'  => [],
+                'total' => 0,
+            ]);
+        }
+
+        $pk = $this->model->getPk();
+
+        // 远程下拉只要求包含主键与可显示字段；这里尽量返回主键 + quickSearch 字段，避免全量字段带来性能问题
+        $fields = [$pk];
+        $quickSearchArr = is_array($this->quickSearchField) ? $this->quickSearchField : explode(',', (string) $this->quickSearchField);
+        foreach ($quickSearchArr as $f) {
+            $f = trim((string) $f);
+            if ($f === '') continue;
+            $f = str_contains($f, '.') ? substr($f, strrpos($f, '.') + 1) : $f;
+            if ($f !== '' && !in_array($f, $fields, true)) {
+                $fields[] = $f;
+            }
+        }
+
+        list($where, $alias, $limit, $order) = $this->queryBuilder();
+        $res = $this->model
+            ->field($fields)
+            ->alias($alias)
+            ->where($where)
+            ->order($order)
+            ->paginate($limit);
+
+        return $this->success('', [
+            'list'  => $res->items(),
+            'total' => $res->total(),
+        ]);
     }
 }

app/common/controller/Backend.php

@@ -214,9 +214,8 @@ class Backend extends Api
     public function select(WebmanRequest $request): Response
     {
         $response = $this->initializeBackend($request);
-        if ($response !== null) return $response;
+        if ($response instanceof Response) return $response;
-        $this->_select();
+        return $this->_select();
-        return $this->success();
     }
 
     /**