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();

     }

}