使用nginx配置alias别名访问phpmyadmin时，为什么会导致文件下载而不是正常显示？

  # 使用 /mysql 访问 phpMyAdmin
  location ^~ /mysql {
    alias /home/wwwroot/default/phpmyadmin/;
    index index.php;
  }

  # 处理PHP文件，但访问时仍下载文件
  location ~ /mysql/.+\.php$ {
      if ($fastcgi_script_name ~ /mysql/(.+\.php.*)$) {
          set $valid_fastcgi_script_name $1;
      }
      include fastcgi_params;
      fastcgi_pass 127.0.0.1:9000;
      fastcgi_index index.php;
      fastcgi_param script_filename /home/wwwroot/default/phpmyadmin/$valid_fastcgi_script_name;
  }

  location ~ \.php(.*)$ {
        fastcgi_pass   127.0.0.1:9000;
        fastcgi_index  index.php;
        fastcgi_split_path_info  ^((?u).+\.php)(/?.+)$;
        fastcgi_param  script_filename  $document_root$fastcgi_script_name;
        fastcgi_param  path_info  $fastcgi_path_info;
        fastcgi_param  path_translated  $document_root$fastcgi_path_info;
        include        fastcgi_params;
  }

location ^~ /mysql {
    proxy_pass http://127.0.0.1:8080;  # 假设phpMyAdmin运行在8080端口
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}