我想检索和操作一些Couchbase文档,即检索并执行一些字符串操作,但我在网上看不到初学者的例子。
我在这里使用正确的方法还是有更简单的方法......?
SELECT meta().id
FROM bucket_foo
where meta().id like "%-foobar"
ORDER BY meta().id
这给了我查询结果...
[
{
"id": "172.26.138.52-foobar"
},
{
"id": "172.26.138.53-foobar"
},
{
"id": "172.26.138.64-foobar"
}
]
我想删除后缀,即将其转换为类似以下内容:
[
{
"id": "172.26.138.52"
},
{
"id": "172.26.138.53"
},
{
"id": "172.26.138.64"
}
]
所以在阅读 https://developer.couchbase.com/documentation/server/4.0/n1ql/n1ql-language-reference/stringfun.html 后我尝试了...
SELECT REPLACE(
(SELECT meta().id FROM foo where meta().id like "%-foobar" ORDER BY meta().id)
, "-foobar", "") as replace_all;
但我得到
[
{
"replace_all": null
}
]
[我是一个完全的沙发新手。
您采用正确的方法,子查询返回数组,并且无法替换数组。在这种情况下,不需要子查询。
您可以使用 RTRIM(( 或 REPLACE(( 或 SUBSTR(( 或类似的函数
SELECT RTRIM(meta().id,"-foobar") AS id
FROM bucket_foo
where meta().id like "%-foobar"
ORDER BY id;
或
SELECT REPLACE(meta().id,"-foobar","") AS id
FROM bucket_foo
where meta().id like "%-foobar"
ORDER BY id;
或
SELECT SUBSTR(meta().id,0,LENGTH(meta().id)-LENGTH("-foobar")) AS id
FROM bucket_foo
where meta().id like "%-foobar"
ORDER BY id;
https://developer.couchbase.com/documentation/server/current/n1ql/n1ql-language-reference/stringfun.html