MongoDB将不同类对象存入同一个Collection

在mongodb中对应关系型数据库中‘表’的概念为‘集合’，表中的数据结构是一致，mongodb以json格式存储，集合数据是灵活的，mongodb的同一集合collection中可存不同结构的数据。下面为项目开发中测试的例子。

1.保存

public void testSave(){


BizEntpris biz = new BizEntpris();
biz.setName("biztest01");

Country country = new Country();
country.setName("chinaName");


mongoTemplate.save(biz, "testMutiCollection");
mongoTemplate.save(country, "testMutiCollection");


BizEntpris biz2 = new BizEntpris();
biz2.setName("biztest02");

Country country2 = new Country();
country2.setName("chinaName02");


mongoTemplate.save(biz2, "testMutiCollection");
mongoTemplate.save(country2, "testMutiCollection");

}

2.查询

public Map<String,Object> testQuery01(){

Map<String,Object> objMap = new HashMap<String, Object>();

Query query = new Query();

query.addCriteria(Criteria.where("name").is("biztest01"));

BizEntpris ent = mongoTemplate.findOne(query, BizEntpris.class, "testMutiCollection");

objMap.put("Entpris",ent);

Query q = new Query();

q.addCriteria(Criteria.where("name").is("chinaName01"));

Country country = mongoTemplate.findOne(q, Country.class, "testMutiCollection");

objMap.put("country", country);

List<Country> countryListAll = mongoTemplate.findAll(Country.class, "testMutiCollection");

objMap.put("countryListAll", countryListAll);//当findAll时查询集合testMutiCollection所有的对象json数据，包含BizEntpris和Country的

List<BizEntpris> entListAll = mongoTemplate.findAll(BizEntpris.class, "testMutiCollection");

objMap.put("EntprisListAll", entListAll);//查询集合testMutiCollection所有的对象json数据，包含BizEntpris和Country的

Query q1 = new Query();
System.out.println(Country.class.getSimpleName());
System.out.println(Country.class.getName());
q1.addCriteria(Criteria.where("_class").is(Country.class.getSimpleName()));

List<Country> countryList = mongoTemplate.find(q1,Country.class, "testMutiCollection");

objMap.put("countryListWithClass", countryList);



Query q2 = new Query();

q2.addCriteria(Criteria.where("_class").is(BizEntpris.class.getName()));

List<BizEntpris> entList = mongoTemplate.find(q2,BizEntpris.class, "testMutiCollection");

objMap.put("EntprisListWithClass", entList);

return objMap;
}