公开分布式高性能查询的源代码和部署方案.(二）

2019独角兽企业重金招聘Python工程师标准>>>

5）创建复杂的对象关联，在Versant数据库中也非常容易，可以直接理解为内存对象的操作。 public void createKnownPerson() { TransSession session = DistributedDatabaseManager.getInstance() .createNewSession(); session.setDefaultDatabase("dbnodeb"); Person personA = new Person(); personA.setFirstName("AAF1"); personA.setLastName("AAL1"); Person personB = new Person(); personB.setFirstName("BBF1"); personB.setLastName("BBL1"); personB.addFriend(personA); Person personC = new Person(); personC.setFirstName("CCF1"); personC.setLastName("CCL1"); personC.addFriend(personB); Person personD = new Person(); personD.setFirstName("DDF1"); personD.setLastName("DDL1"); personD.addFriend(personC); session.makePersistent(personA, "dbnodea"); session.makePersistent(personB, "dbnodeb"); session.makePersistent(personC, "dbnodea"); session.makePersistent(personD, "dbnodeb"); System.out.println("Special Test Data created."); session.commit(); } 6）Versant数据库的对象查询 Versant数据库可以支持SQL查询和NOSQL查询两种模式，以下为SQL查询的例子： TransSession session = DistributedDatabaseManager.getInstance() .createNewSession(); VQLQuery q = new VQLQuery( session, DistributedDatabaseManager.getInstance().HPC_DEMO_NETWORK_NAME, "select selfoid from com.versant.domain.Person where firstName='AAF1' and lastName='AAL1'"); //"select * from com.versant.domain.Person"); System.out.println("About to execute query, and load root object."); VEnumeration results = q.execute(); // 创建已经走过的朋友路径，避免回环 System.out .println("--------------------------------------------------------------------------");

转载于:https://my.oschina.net/u/267705/blog/54814