如何在Java中使用列表从Aerospike获取记录？

Question

在 test.setName 函数中，我的数据长这样：

| id    | cities              | lob        |
|-------|---------------------|------------|
| id123 | ["Cthdcn","Ctdel"]  | ["Lob132"] |
| id345 | ["Ctijs","Ctdelhi"] | ["LOB231"] |
| id765 | ["Cthui"]           | ["Lob875"] |

"

"cities"已经存在于列表索引中，我想通过指定类似(["Ctijs"，"Ctdelhi"]）的城市数组，通过java客户端获取特定记录。

我想使用以下方法通过指定城市数组来检索（获取）记录，该方法将使用java。

"

    public Record testGet(String namespace, String set, String city, List<String> binNames) {
    Statement statement = new Statement();
    statement.setNamespace(namespace);
    statement.setSetName(set);
    Filter filter = Filter.contains("cities", IndexCollectionType.LIST, city);
    statement.setFilter(filter);
    RecordSet records = this.client.query((QueryPolicy)null, statement);
    return records.getRecord();
}

我得到了NULL。如何检索那个特定的记录？（AQL版本3.23.0）

- Vrishank Gupta

---

在上述代码中，你在testGet()函数中传递了哪个字符串city的参数？ - pgupta

@pgupta 我将"Cthui"作为字符串城市传递了。 - Vrishank Gupta

在AQL中，此查询语句“select lob from test.setName in LIST where cities = 'Cthui'”运行良好。 - Vrishank Gupta

Answer 1

以下是文本文件list.aql中的一小段AQL脚本，可以复制您的测试：

list.aql:

TRUNCATE test
DROP INDEX test.setName idx_city
SELECT * FROM test
CREATE LIST INDEX idx_city ON test.setName (cities) STRING

INSERT INTO test.setName (PK, id, cities, lob) VALUES ('key1', 'id123', LIST('["Cthdcn", "Ctdel"]'), LIST('["Lob132
"]'))
INSERT INTO test.setName (PK, id, cities, lob) VALUES ('key2', 'id345', LIST('["Ctijs", "Ctdelhi"]'), LIST('["LOB23
1"]'))
INSERT INTO test.setName (PK, id, cities, lob) VALUES ('key3', 'id765', LIST('["Cthui"]'), LIST('["Lob875"]'))

select * from test.setName

select * from test.setName in LIST where cities = 'Cthdcn'

AQL中的输出：

aql> run 'list.aql'
TRUNCATE test
OK

DROP INDEX test.setName idx_city
Error: (201)  Index does not exist on the system.

SELECT * FROM test
0 rows in set (0.156 secs)

OK

CREATE LIST INDEX idx_city ON test.setName (cities) STRING
OK, 1 index added.

INSERT INTO test.setName (PK, id, cities, lob) VALUES ('key1', 'id123', LIST('["Cthdcn", "Ctdel"]'), LIST('["Lob132"]'))
OK, 1 record affected.

INSERT INTO test.setName (PK, id, cities, lob) VALUES ('key2', 'id345', LIST('["Ctijs", "Ctdelhi"]'), LIST('["LOB231"]'))
OK, 1 record affected.

INSERT INTO test.setName (PK, id, cities, lob) VALUES ('key3', 'id765', LIST('["Cthui"]'), LIST('["Lob875"]'))
OK, 1 record affected.

select * from test.setName
+---------+------------------------------+--------------------+
| id      | cities                       | lob                |
+---------+------------------------------+--------------------+
| "id123" | LIST('["Cthdcn", "Ctdel"]')  | LIST('["Lob132"]') |
| "id765" | LIST('["Cthui"]')            | LIST('["Lob875"]') |
| "id345" | LIST('["Ctijs", "Ctdelhi"]') | LIST('["LOB231"]') |
+---------+------------------------------+--------------------+
3 rows in set (0.124 secs)

OK

select * from test.setName in LIST where cities = 'Cthdcn'
+---------+-----------------------------+--------------------+
| id      | cities                      | lob                |
+---------+-----------------------------+--------------------+
| "id123" | LIST('["Cthdcn", "Ctdel"]') | LIST('["Lob132"]') |
+---------+-----------------------------+--------------------+
1 row in set (0.001 secs)

OK

aql>

在Java中，您需要迭代记录集以获取满足查询条件的每个记录。

RecordSet records = client.query( .....)
while (records.next()){
  Record r = records.getRecord();
  ....
}
records.close()

我刚刚测试了以下代码：

public void read () {
                Record record = null;
                Statement stmt = new Statement();
                stmt.setSetName("setName");
                stmt.setNamespace("test");
                stmt.setIndexName("idx_city");
                stmt.setFilter(Filter.contains("cities", IndexCollectionType.LIST, "Cthui"));

                RecordSet recordSet = this.client.query(queryPolicy, stmt);
            while (recordSet.next()) {
                record = recordSet.getRecord();
                System.out.println(record.toString());
            }

         }

而且它对我很有效。

$ java -jar ./target/dm-predicateFilter-1.0-full.jar
(gen:1),(exp:348432597),(bins:(id:id765),(cities:[Cthui]),(lob:[Lob875]))

- pgupta