定向多次遍历

Question

我有这张图：

我正在尝试使用 OrientDB v3.0 的 "SQL Syntax" 编写查询，该查询从客户端开始并遵循读取路径（X 表示： 并且不与客户有 Have 关系)。

我可以获取细分，但找不到如何走到联系人。 docs have many examples却只走一条路

我试过这些查询但没有成功：

SELECT FROM  (TRAVERSE out("Access").out("Contain") FROM (SELECT @rid FROM Client where myId = 30543) MAXDEPTH 1)


SELECT FROM (
    TRAVERSE out("Contain") FROM
        (TRAVERSE out("Access") FROM (SELECT @rid FROM Client where myId = 30543) MAXDEPTH 1)
    MAXDEPTH 1
)

SELECT out('Access').out("Contain") FROM Client WHERE myId = 30543

你有完成这次穿越的任何信息吗？

我正在使用 Node.js API:

const pool = await orient.getPool();
const session = await pool.acquire();

logger.info('Running query...');
session.command(`SELECT out('Access').out("Contain") FROM Client WHERE myId = 30543`)
  .on('data', (data) => {
    if (data.out_Contain && data.out_Contain.delegate) {
      logger.info('Segment %s contains %o Contact', data['@rid'].toString(), data.out_Contain.delegate.size);
    } else if (data['@rid']) {
      logger.info('Segment %s contains %o Contact', data['@rid'].toString(), data);
    } else {
      logger.info('Data %o', data);
    }
  })
  .on('error', (err) => {
    logger.error(err);
  })
  .on('end', () => {
    console.timeEnd('query');
    logger.info('End of the stream');
    process.emit('SIGINT');
  });

logger.debug('Registering SIGINT');
process.once('SIGINT', async () => {
  await session.close();
  await pool.close();
  await orient.stop();
});

Answer 1

请尝试使用此代码：

"select out_{edgeclass}.in from (select expand(out_{edgeclass}.in) from {Vetex} where {condition})"

Answer 2

match 更适合此类任务。

与SELECT:

In the first version, the query is more readable, but it does not use indexes, so it is less optimal in terms of execution time. The second and third use indexes if they exist, (on Person.name or City.name, both in the sub-query), but they're harder to read. Which index they use depends only on the way you write the query.

但匹配：

the query executor optimizes the query for you, choosing indexes where they exist. Moreover, the query becomes more readable, especially in complex cases, such as multiple nested SELECT queries.

这里是正确的查询：

SELECT EXPAND(contatti) 
    FROM ( 
      match { class: Client, as: user, where : ( myId = 30543)}
        .out('Access')
        .out('Contain'){ class:Contact, as:contatti, where: (gender= 'M')},
      NOT {as:user} -Have-> {as:contatti} 
      RETURN DISTINCT contatti LIMIT 1000
    )

定向多次遍历

Orient multiple traverse

node.js

orientdb