Question

我正在尝试从Couchbase示例啤酒样本中查询。

此查询在Couchbase浏览器用户界面中运行良好：

select category, style from `beer-sample` where style like 'Imperial%'

结果：

[
  {
    "category": "North American Ale",
    "style": "Imperial or Double India Pale Ale"
  },
...
]

但是当我将查询移植到Java中时，会得到非常奇怪的结果。（是的，我知道我在错误的位置打开/关闭连接，只是这样做是为了快速探索Couchbase的语法/功能。）

Java代码：

@RequestMapping("/hellocouchbase")
public ResponseEntity<List<JsonObject>> metrics() {

    Cluster cluster = CouchbaseCluster.create();
    cluster.authenticate(username, passwd);

    Bucket bucket = cluster.openBucket("beer-sample");

    N1qlQueryResult result = bucket.query(N1qlQuery.simple("select category, style from `beer-sample` where style like 'Imperial%'"));

    List<N1qlQueryRow> results = result.allRows();      
    List<JsonObject> answer = new ArrayList<>(results.size());

    for(N1qlQueryRow row:results) {
        answer.add(row.value());
    }

    cluster.disconnect();       
    return ResponseEntity.status(200).body(answer);
}

结果：

[
{"cryptoManager":null,"empty":false,"names":["style","category"]},{"cryptoManager":null,"empty":false,"names":["style","category"]},
...
]

有人可以解释如何使java查询产生与直接查询相同的结果吗？

Answer 1

尝试创建一个新用户并向其添加所有特权（只是确保您没有遇到任何安全限制）。

您的代码对我有用：

    Cluster cluster = CouchbaseCluster.create();
    cluster.authenticate("test", "couchbase"); //user and password that I created

    Bucket bucket = cluster.openBucket("beer-sample");

    N1qlQueryResult result = bucket.query(N1qlQuery.simple("select category, style from `beer-sample` where style like 'Imperial%'"));

    List<N1qlQueryRow> results = result.allRows();
    List<JsonObject> answer = new ArrayList<>(results.size());

    for(N1qlQueryRow row:results) {
        answer.add(row.value());
        System.out.println(row);
    }

    cluster.disconnect();

输出：

{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
...
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
{"category":"North American Ale","style":"Imperial or Double Red Ale"}
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}
{"category":"North American Ale","style":"Imperial or Double India Pale Ale"}

Answer 2

出于某种原因，对此进行更改

answer.add(row.value());

对此

answer.add(row.value().toMap());

为我修复了它。考虑到原始版本显然适合此处的其他人，所以不知道为什么。

完整的解决方案供参考：

@RequestMapping("/hellocouchbase")
public ResponseEntity<List<Map<String,Object>>> metrics() {

    Cluster cluster = CouchbaseCluster.create();
    cluster.authenticate(username, passwd);

    Bucket bucket = cluster.openBucket("beer-sample");

    N1qlQueryResult result = bucket.query(N1qlQuery.simple("select category, style from `beer-sample` where style like 'Imperial%'"));

    List<N1qlQueryRow> results = result.allRows();      
    List<Map<String,Object>> answer = new ArrayList<>(results.size());

    for(N1qlQueryRow row:results) {
        answer.add(row.value().toMap());
    }

    cluster.disconnect();       
    return ResponseEntity.status(200).body(answer);
}

如何使用Java API查询Couchbase

2 个答案: