有没有办法将包含 UNION + TOP + ORDER BY 的 SQL 转换为 Elasticsearch DSL

Question

我是 ElasticSearch 的新手，我想知道是否有办法将以下 SQL 转换为 Elasticsearch DSL：

SELECT TOP 3 1 as Priority, * FROM Customers where ContactName like 'A%' 
UNION
SELECT TOP 3 2 as Priority, * FROM Customers where NOT(ContactName like 'A%')
ORDER BY Priority, ContactName ASC;

另外，我想知道是否有一个选项可以将此查询扩展到 SQL 不支持的内容...以不同的顺序对每个查询进行排序（据我所知无法在SQL），所以从概念上讲，SQL 看起来像：

(SELECT TOP 3 1 as Priority, * FROM Customers where ContactName like 'A%'ORDER BY Priority, City ASC) 
UNION
(SELECT TOP 3 2 as Priority, * FROM Customers where NOT(ContactName like 'A%')
ORDER BY Priority, ContactName ASC);

注意：我更喜欢将所有响应对象作为一个响应来获取，而不是作为与特定源查询相关联的响应列表（类似于我将从上面的 SQL 语句中获得的响应）。

Answer 1

更好的办法是给你两个查询或msearch

替代方法是使用terms aggregation

{
  "size": 0, 
  "aggs": {
    "cities": {
      "terms": {
        "field": "city-name.keyword",
        "size": 10,
        "order": {
          "_term": "asc"
        }
      },
      "aggs": {
        "starts_with_A": {
          "terms": {
            "field": "customer-name.keyword",
            "include": "A.*",
            "size": 5
          }
        }
      }
    },
    "starts_Not_with_A": {
      "terms": {
        "field": "customer-name.keyword",
        "exclude": "A.*",
        "size": 10,
        "order": {
          "_term": "asc"
        }
      }
    }
  }
}