Query DSL(Domain Specific Language) 用来描述数据查询条件，适用基于数据库实现的数据分析引擎，如 Xu 等。

数据查询的数据类型为 Object QueryDSL，通过 select, wheres 等字段描述查询条件，解析器将其转换为对应的 SQL语句。

数据表 service :

function Service() {
  var query = new Query();
  var data = query.Get({
    comment: "统计各行业最高分",
    select: ["industries", "city", ":MAX(score) as high_score"],
    from: "service",
    wheres: [
      { ":created_at": "创建时间", ">=": "2021-01-01" },
      { ":created_at": "创建时间", "<=": "2025-01-01" },
      { ":updated_at": "更新时间", is: "null" },
      {
        wheres: [
          { ":type": "类型", "=": 1 },
          { "or:type": "或类型", "=": 2 },
        ],
      },
    ],
    orders: "high_score desc",
    limit: 100,
    groups: ["industries", "city"],
  });
  return data;
}

解析后的 SQL语句 为 (MySQL 8):

SELECT `industries`, `city`, MAX(`score`) AS `high_score`
FROM `service`
WHERE `created_at` >= '2021-01-01'
AND `created_at` <= '2025-01-01'
AND `updated_at` is null
AND (`type` = ?)
GROUP BY `industries`, `city`
ORDER BY `high_score` DESC