MongoDB 有关实体映射具体应用及对查询的影响

1 创建实体的时候，可以用注解@Document 对实体进行设置，指定集合名字

/**
 *
 */
package com.cfj.ceshi.entity;

import org.springframework.data.mongodb.core.mapping.Document;

@Document(collection="etlCheckInfo")
public class Contrast {

    private static final long serialVersionUID = 1L;

    private String checkId;
    private String readNum;
    private String volume;
    private String weight;

    public String getCheckId() {
        return checkId;
    }
    public void setCheckId(String checkId) {
        this.checkId = checkId;
    }
    public String getReadNum() {
        return readNum;
    }
    public void setReadNum(String readNum) {
        this.readNum = readNum;
    }
    public String getVolume() {
        return volume;
    }
    public void setVolume(String volume) {
        this.volume = volume;
    }
    public String getWeight() {
        return weight;
    }
    public void setWeight(String weight) {
        this.weight = weight;
    } 

}

如果不用注解指定集合名称，在保存方法的时候也没有指定集合名称，那么第一次创建集合的时候，集合名字就是实体名字contrast

如果利用注解指定了集合名称，在保存或查询等方法的时候，则不需要显示指定集合名称，默认会保存实体被注解的集合名字中去

package com.cfj.ceshi.dao.impl;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;
import org.springframework.data.mongodb.core.query.Update;
import org.springframework.stereotype.Component;

import com.cfj.ceshi.dao.UserDao;
import com.cfj.ceshi.entity.UserEntity;
import com.mongodb.WriteResult;

@Component
public class UserDaoImpl implements UserDao{

    @Autowired
    private MongoTemplate mongoTemplate;

    @Override
    public void saveUser(UserEntity user) {
        mongoTemplate.save(user);
        //mongoTemplate.save(user, "jihe01");//指定集合

    }

}