ES：按日期排序字段需要启用fielddata

Question

我正在尝试获取按 updated_at 字段排序的索引的所有匹配项。

然而，下面显示的错误信息说明了这一点： "{"error":{"root_cause":[{"type":"illegal_argument_exception","reason":"Fielddata is disabled on text fields by default. Set fielddata=true on [updated_at] in order to load fielddata in memory by uninverting the inverted index.

这是我正在使用的映射：

Map::create($this->getModelType(), function (Blueprint $map) {
            $map->integer('id');
            $map->addField('text', 'title');
            $map->date('created_at')->format('yyyy-MM-dd HH:mm:ss');
            $map->date('updated_at')->format('yyyy-MM-dd HH:mm:ss');
            $map->date('deleted_at')->format('yyyy-MM-dd HH:mm:ss');
}));

这是获取所有通过 updated_at字段排序的数据的代码：

 $titleData = $this->title->search()->sortBy('updated_at', 'DESC');

有什么想法吗？

Answer 1

Seems like in ElasticSearch index updated_at is stored as text. Text fields are analyzed and normally ElasticSearch cannot sort by those fields, because fielddata is disabled on text fields by default.

In order to overcome it you can create mapping with keyword type. It might look like this:

"updated_at": {
  "type": "text", // assuming you originally have it as text
  "fields": {
    "original": "keyword",
    "ignore_above": 64 // You can skip or change it and ES applies default value. 
  }
}

And then you should use mapping for sorting. You can access it like this: updated_at.original.