Mybatis Criteria条件查询 Mybatis中的Criteria条件查询方式

import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;
 
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.apache.log4j.pattern.ClassNamePatternConverter;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
 
import cn.itcast.ssm.mapper.ItemsMapper;
import cn.itcast.ssm.po.ItemsExample; 
public class Student { 
    public static void main(String[] args) throws IOException {
        /*方式一  */
        ItemsExample itemsExample1 = new ItemsExample();
        itemsExample1.or().andIdEqualTo(5).andNameIsNotNull();
        itemsExample1.or().andPicEqualTo("xxx").andPicIsNull();
 
        List<Integer> fieldValues = new ArrayList<Integer>();
        fieldValues.add(8);
        fieldValues.add(11);
        fieldValues.add(14);
        fieldValues.add(22);
        itemsExample1.or().andIdIn(fieldValues);
        itemsExample1.or().andIdBetween(5, 9);
 
        /*  方式二 criteria1与criteria2是or的关系 */
        ItemsExample itemsExample2 = new ItemsExample();
        ItemsExample.Criteria criteria1 = itemsExample2.createCriteria();
        criteria1.andIdIsNull();
        criteria1.andPriceEqualTo((float) 3);
 
        ItemsExample.Criteria criteria2 = itemsExample2.createCriteria();
        criteria2.andNameIsNull();
        criteria2.andIdGreaterThanOrEqualTo(5);
        itemsExample2.or(criteria2);
 
        //方式一和方式二是等价的 
        // spring获取mapper代理对象
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
        ItemsMapper itemsMapper = (ItemsMapper) applicationContext.getBean("itemsMapper");
        itemsMapper.countByExample(itemsExample2);
 
        // 获取SqlSessionFactory
        String resource = "SqlMapConfig.xml";
        Reader reader = Resources.getResourceAsReader(resource);
        SqlSessionFactory sqlMapper = new SqlSessionFactoryBuilder().build(reader);
        // 获取SqlSession
        SqlSession sqlSession = sqlMapper.openSession();
    }
}