MongodbTemplate的查詢操作

2021-09-21 04:03:41 字數 4055 閱讀 3130

class類

@document(collection = "class")


public


class


class 


public


void


setclassid(string classid) 


public string getteacher()


public


void


setteacher(string teacher)


public listgetstudents() 


public


void


setstudents(liststudents) 


@override


public string tostring() 


}
查詢滿足條件的資料

query query = query.query(criteria.where("classid").is("1"));


listclasss = mongotemplate.find(query,class.class,"class");


system.out


.println(classs);
查詢滿足條件的第一條資料

query query = query.query(criteria.where("classid").is("1"));


listclasss = mongotemplate.findone(query,class.class,"class");


system.out


.println(classs);
篩選要查詢的字段（id欄位不查出來）

dbobject dbobject = new basicdbobject();


dbobject.put("classid", "1");


dbobject fieldobject = new basicdbobject();


fieldobject.put("_id", false);


query query = new basicquery(dbobject, fieldobject);


listclasss = mongotemplate.find(query,hashmap.class,"class");


system.out.println(classs);
當然也可以不使用hashmap,而使用自己封裝的dto，那麼只會查詢出dto中的字段。

查詢結果排序

dbobject dbobject = new basicdbobject();


dbobject.put("classid", "1");


dbobject fieldobject = new basicdbobject();


fieldobject.put("_id", false);


query query = new basicquery(dbobject);


query.with(new sort(direction.asc,"classid"));


listclasss = mongotemplate.find(query,hashmap.class,"class");


system.out.println(classs);
多欄位排序

dbobject dbobject = new basicdbobject();


dbobject.put("classid", "1");


dbobject fieldobject = new basicdbobject();


fieldobject.put("_id", false);


query query = new basicquery(dbobject);


list.order> orders = new arraylist<>();


orders.add(new sort.order(direction.desc, "classid"));


orders.add(new sort.order(direction.desc, "teacher"));


query.with(new sort(orders));


listclasss = mongotemplate.find(query,hashmap.class,"class");


system.out


.println(classs);
查詢結果分頁

int pagenum = 1


;int pagesize = 10


;dbobject dbobject = new basicdbobject();


dbobject.put("classid", "1");


dbobject fieldobject = new basicdbobject();


fieldobject.put("_id", false);


query query = new basicquery(dbobject,fieldobject);


list.order> orders = new arraylist<>();


orders.add(new sort.order(direction.asc, "classid"));


orders.add(new sort.order(direction.desc, "teacher"));


query.with(new sort(orders));


query.skip(pagesize*(pagenum-1)).limit(pagesize);


listclasss = mongotemplate.find(query,hashmap.class,"class");


system.out


.println(classs);
還有一種通過morphia框架的做法：

int pagenum = 1


;int pagesize = 10


;dbobject dbobject = new basicdbobject();


dbobject.put("teacher", "mr.wang");


dbobject fieldobject = new basicdbobject();


fieldobject.put("_id", false);


fieldobject.put("_class", false);


dbobject sortdbobject=new basicdbobject();  


sortdbobject.put("classid",1);  


dbcursor result = mongotemplate.getcollection("class")


.find(dbobject, fieldobject)


.sort(sortdbobject)


.skip(pagesize*(pagenum-1)).limit(pagesize);


system.out


.println(result.count());


system.out


.println(result.toarray());
多條件查詢

我們只需要對query物件做出處理即可

criteria criteria = new criteria(); criteria.oroperator(criteria.where("classid").is("2"),criteria.where("teacher").is("mr.wang"));


criteria.andoperator(criteria.where("classid").is("2"));


query.addcriteria(criteria);

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