Couchbase 如何编写一个n1ql查询来对同一存储桶中多个文档的值求和

我是Couchbase DB服务器的新手，我正试图用一个查询实现我用三个查询所做的，因为这不是很有效

我在同一个桶中有三种不同的文档类型（x、y、z）；都有一个类似的键：“district”如下：

文件十：

{
  "type": "x",
  "district": "Some district"
}

文件y：

{
  "type": "y",
  "district": "Some district"
}

文件z：

{
  "type": "z",
  "district": "Some district"
}

我目前已经在PHP中实现了类似以下的伪代码：

$totalDistrictInX = "SELECT COUNT(x) FROM bucket WHERE type = 'x' AND district = 'Maboro';

$totalDistrictInY = "SELECT COUNT(x) FROM bucket WHERE type = 'y' AND district = 'Maboro';

$totalDistrictInZ = "SELECT COUNT(x) FROM bucket WHERE type = 'z' AND district = 'Maboro';

$totalCountOfMaboro = $totalDistrictInX + $totalDistrictInY + $totalDistrictInZ;

我无法使用联接查询，因为当前使用的Couchbase服务器低于5.50

---

有没有一种方法可以通过一个n1ql查询实现这一点？任何帮助都将不胜感激。

您可以通过

分组和
计数组合解决问题吗

SELECT COUNT(x) FROM bucket WHERE district = 'Maboro' GROUP BY type

您的解决方案是否可以是
分组依据
和
计数
组合

SELECT COUNT(x) FROM bucket WHERE district = 'Maboro' GROUP BY type

使用不带分组依据的聚合查询进行总计数，通过谓词控制要计数的文档

SELECT COUNT(1) AS cnt
FROM bucket
WHERE type IN ['x', 'y', 'z'] AND district = 'Maboro';

如果您需要每种类型的计数，请使用分组方式

SELECT type, COUNT(1) AS cnt
FROM bucket
WHERE type IN ['x', 'y', 'z'] AND district = 'Maboro'
GROUP BY type;

如果您想要总计数和单个类型，则其计数为数组

SELECT ARRAY_SUM(av[*].cnt) AS totalcnt, av AS details
LET av = (SELECT type, COUNT(1) AS cnt
          FROM bucket
          WHERE type IN ['x', 'y', 'z'] AND district = 'Maboro'
          GROUP BY type);

对总计数使用不带分组的聚合查询，通过谓词控制要计数的文档

SELECT COUNT(1) AS cnt
FROM bucket
WHERE type IN ['x', 'y', 'z'] AND district = 'Maboro';

如果您需要每种类型的计数，请使用分组方式

SELECT type, COUNT(1) AS cnt
FROM bucket
WHERE type IN ['x', 'y', 'z'] AND district = 'Maboro'
GROUP BY type;

如果您想要总计数和单个类型，则其计数为数组

SELECT ARRAY_SUM(av[*].cnt) AS totalcnt, av AS details
LET av = (SELECT type, COUNT(1) AS cnt
          FROM bucket
          WHERE type IN ['x', 'y', 'z'] AND district = 'Maboro'
          GROUP BY type);

感谢你的努力，但这不起作用。@vsr.给出的答案表示感谢，但这不起作用。答案是@vsr。