Question

我在Go中编写了一种类似REST的API。我拥有的数据库是遗留的，因此我无法控制字段名称或结构或任何事情。我在一个名为datastore的独立包中抽象数据库访问方法。我的代码看起来像这样（跳过所有错误处理等）。

type Datastore struct {}

type Object struct {
  id uint
  name string
  ... zillion more fields here
}

func (Datastore) ObjectList() {
  var objects *[]Object
  db, _ := sqlx.Open("postgres", conn_info)
  rows, _ := sqlx.Queryx("SELECT * FROM object_table")
  defer rows.Close()
  for rows.Next() {
    var obj Object
    rows.Scan(&obj.id, &obj.name)
    objects = append(objects, obj)
  }
  return objects
}

我目前遇到的问题是对象表有几十个字段。有些我关心，但有些我不关心。有些名称与Object相同，有些则不是。最终，我需要支持其中的大多数，但我首先要进行概念验证。如果扫描代码在行中找到的字段多于Scan（）参数中的字段，则扫描代码似乎失败。我可以在查询select id, name from object_table中列出我扫描的字段，但是 1.它使代码非常难看（SQL没有通过gofmt格式化） 2.当我想支持另一个字段时，它会添加我需要编辑的另一个地方

有没有办法实现一个自定义扫描程序接口，该接口将获取行对象，将一些数据加载到结构中并忽略其余部分？

Answer 1

您已经在使用sqlx，所以在查询之前只需使用* DB.Unsafe（）：

<div id="feather-prods" class="row">
                <div id="div1">
                <div id="prod-stop" class="col-md-5 col-sm-6 col-xs-8 col-xs-push-2 col-sm-push-1 col-md-push-1">
                    <div class="prod-img"><img id="tab1show" class="tab-content bigImg" src="images/broom/monara-pp-1.jpg" alt="feather, Purple monara broom"></div>

                    <div class="thumbnailImg">
                      <div id="tab1show" class="tab-content thumb"><img src="images/broom/monara-pp-1.jpg" alt="feather, Purple monara broom" border="0" width="100%" class="thumbImg" /></div>
                      <div id="tab1show" class="tab-content thumb"><img src="images/broom/monara-pp-2.jpg" alt="feather, Purple monara broom" border="0" width="100%" class="thumbImg" /></div>
                      <div id="tab1show" class="tab-content thumb"><img src="images/broom/monara-pp-3.jpg" alt="feather, Purple monara broom" border="0" width="100%" class="thumbImg" /></div>
                      <div id="tab1show" class="tab-content thumb"><img src="images/broom/monara-pp-4.jpg" alt="feather, Purple monara broom" border="0" width="100%" class="thumbImg" /></div>
                    </div>
                </div>
                </div>

                <div id="div2" style="display:none;" >
                <div id="prod-stop" class="col-md-5 col-sm-6 col-xs-8 col-xs-push-2 col-sm-push-1 col-md-push-1">
                    <div class="prod-img"><img id="tab2show" class="tab-content bigImg" src="images/broom/monara-b-1.jpg" alt="feather, black monara broom"></div>

                    <div class="thumbnailImg">
                      <div id="tab2show" class="tab-content thumb"><img src="images/broom/monara-b-1.jpg" alt="feather, black monara broom" border="0" width="100%" class="thumbImg" /></div>
                      <div id="tab2show" class="tab-content thumb"><img src="images/broom/monara-b-2.jpg" alt="feather, black monara broom" border="0" width="100%" class="thumbImg" /></div>
                      <div id="tab2show" class="tab-content thumb"><img src="images/broom/monara-b-3.jpg" alt="feather, black monara broom" border="0" width="100%" class="thumbImg" /></div>
                      <div id="tab2show" class="tab-content thumb"><img src="images/broom/monara-b-4.jpg" alt="feather, black monara broom" border="0" width="100%" class="thumbImg" /></div>
                    </div>
                </div><!-- prod images end -->
                </div>
</div>

Go

1 个答案: