在Aerospike中查询地图的关键

Question

我正在尝试在aerospike中存储地图并根据地图的关键字获取数据.

首先,我在bin上创建了一个Index,我正在存储地图

 aql> create mapkeys index status on test.myset (state) String
 aql> show indexes
+--------+---------+-----------+---------+-------+-----------+---------+------------+----------+
| ns     | bin     | indextype | set     | state | indexname | path    | sync_state | type     |
+--------+---------+-----------+---------+-------+-----------+---------+------------+----------+
| "test" | "state" | "MAPKEYS" | "myset" | "RW"  | "status"  | "state" | "synced"   | "STRING" |
+--------+---------+-----------+---------+-------+-----------+---------+------------+----------+
1 row in set (0.000 secs)
OK

然后我用java客户端来存储地图

AerospikeClient client = new AerospikeClient("127.0.0.1",3000);

    WritePolicy writePolicy = new WritePolicy();
    writePolicy.timeout=500;

    for(int i = 1;i<10;i++){
        Key key = new Key("test","myset",""+i);
        client.delete(writePolicy, key);

        HashMap<String,String> map = new HashMap<String,String>();
        map.put("key1", "string1");
        map.put("key2", "string2");
        map.put("key3", "string3");

        Bin bin = new Bin("state", map);
        client.put(writePolicy, key, bin);

    }

我通过apl检查数据,数据显然存在.

aql> select * from test.myset
+--------------------------------------------------------+
| state                                                  |
+--------------------------------------------------------+
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
| {"key1":"string1", "key2":"string2", "key3":"string3"} |
+--------------------------------------------------------+
10 rows in set (0.019 secs)

现在,当我尝试根据创建的索引进行查询时,它给出了

aql> select * from test.myset where status = 'key1'
0 rows in set (0.000 secs)
Error: (204) AEROSPIKE_ERR_INDEX

aql> select * from test.myset where state = 'key1'
0 rows in set (0.000 secs)
Error: (201) AEROSPIKE_ERR_INDEX_NOT_FOUND

有人可以帮我弄这个吗.我搜索了这个错误,但没有找到任何信息.谢谢.

Answer 1

除了Numeric,String和Geo2DSphere类型之外,Aerospike还支持MapKeys,MapValues,Lists上的二级索引.

对于您的方案,您可以按如下方式查询Mapkey.

select * from test.myset in mapkeys where state='key1'

这应该返回结果.

在AQL中,如果键入help,则应获取以下查询

    SELECT <bins> FROM <ns>[.<set>]
    SELECT <bins> FROM <ns>[.<set>] WHERE <bin> = <value>
    SELECT <bins> FROM <ns>[.<set>] WHERE <bin> BETWEEN <lower> AND <upper>
    SELECT <bins> FROM <ns>[.<set>] WHERE PK = <key>
    SELECT <bins> FROM <ns>[.<set>] IN <indextype> WHERE <bin> = <value>
    SELECT <bins> FROM <ns>[.<set>] IN <indextype> WHERE <bin> BETWEEN <lower> AND <upper>

同样,您也可以运行MapValue的查询.