N1QL将许多子行连接为单个字符串 [英] N1QL Concatenate many children rows into single string

问题描述

考虑到Couchbase，我有一个人员数据库，其中包含3个文档:

Consider in Couchbase I have a person database, with 3 documents:

Person A
    Child AA
        Grand AAA
        Grand AAB
    Child AB
        Grand ABA
        Grand ABB

Person B

Person C
    Child CA
    Child CB
        Grand CBA

是否有一种简单的方法可以使用N1QL将其转换为以下结果?我正在尝试将每个人和他们的大孩子展示成字符串吗?

Is there an easy way to turn this into following results using N1QL? I am trying to display each person with their grand children displayed into strings?

Person A, Grand: "AAA, AAB, ABA, ABB"
Person B, Grand: ""
Person C, Grand: "CBA"

推荐答案

您可以执行以下操作:

SELECT p.name AS p, ENCODE_JSON(ARRAY_AGG(g.name)) AS g
FROM person AS p LEFT OUTER UNNEST p.child AS c LEFT OUTER UNNEST c.grand AS g
GROUP BY p;

这篇关于N1QL将许多子行连接为单个字符串的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！