mybatis批量增删改——（十五）

1.首先应该明白，mybatis增删改返回值是int型的影响行数的值

mapper接口

package cn.xm.mapper;

import java.util.List;

import cn.xm.pojo.Questions;


/**
 * 自定义的批量删除与批量增加试题
 * @author liqiang
 *
 */
public interface QuestionsCustomMapper {
    /**
     * 批量导入试题
     * @param list 需要倒入的试题集合
     * @return
     * @throws Exception
     */
    public int saveQuestionBatch()throws Exception; 

}

 mapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<!-- namespace命名空间，作用就是对sql进行分类化管理，理解sql隔离 注意：使用mapper代理方法开发，namespace有特殊重要的作用 -->
<mapper namespace="cn.xm.mapper.QuestionsCustomMapper">

    <insert id="saveQuestionBatch">
        INSERT INTO `exam`.`questions`
        VALUES ('7',
        '1',
        '测试题目7',
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        "安全知识")
    </insert>

</mapper>

测试代码:

package cn.xm.test.mybatis;

import java.io.InputStream;
import java.net.URL;
import java.util.Date;
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.tomcat.jdbc.pool.interceptor.SlowQueryReportJmxMBean;
import org.junit.Before;
import org.junit.Test;

import cn.xm.mapper.EmployeeInMapper;
import cn.xm.mapper.QuestionsCustomMapper;
import cn.xm.pojo.EmployeeIn;
import cn.xm.pojo.EmployeeInExample;

public class MybatisTest2 {

    private SqlSessionFactory sqlSessionFactory;

    @Before
    public void setUp() throws Exception {
        // 将全局配置文件作为一个流
        String resource = "sqlMapConfig.xml";
        String realPath = this.getClass().getClassLoader().getResource("sqlMapConfig.xml").getPath();
        InputStream inputStream = Resources.getResourceAsStream(resource);
        // 建立一个SqlSession工厂
        sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
    }

    // 测试增加
    @Test
    public void testAdd() throws Exception {
        SqlSession sqlSession = sqlSessionFactory.openSession();
        QuestionsCustomMapper qsm = sqlSession.getMapper(QuestionsCustomMapper.class);
        int total = qsm.saveQuestionBatch();
        System.out.println(total);
        sqlSession.commit();
        sqlSession.close();
    }

}

结果:

2.批量增加

　　sql语句:　　insert into xxx values ("xx1",'xxx1'),("xx2","xxx2"),("xx3","xxx3")

mapper接口

/**
     * 批量导入试题
     * @param list 需要倒入的试题集合
     * @return 影响的行数
     * @throws Exception
     */
    public int saveQuestionBatch(List<Questions> list)throws Exception;

xml配置

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<!-- namespace命名空间，作用就是对sql进行分类化管理，理解sql隔离 注意：使用mapper代理方法开发，namespace有特殊重要的作用 -->
<mapper namespace="cn.xm.mapper.QuestionsCustomMapper">

    <!-- INSERT INTO `exam`.`questions` VALUES ('7', '1', '测试题目7', NULL, NULL, 
        NULL, NULL, NULL, NULL, NULL, NULL, "安全知识") -->
    <insert id="saveQuestionBatch" parameterType="java.util.List">
        INSERT INTO `exam`.`questions`
        VALUES
        <foreach collection="list" item="question" separator=",">
            (#{question.questionid},#{question.questionbankid},#{question.question},#{question.questionwithtag},#{question.answer},#{question.analysis},#{question.type},#{question.level},#{question.employeeid},#{question.uploadtime},#{question.status},#{question.knowledgetype})
        </foreach>
    </insert>


</mapper>

测试代码:

package cn.xm.test.mybatis;

import java.io.InputStream;
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.junit.Before;
import org.junit.Test;

import cn.xm.bean.basebean.Questions;
import cn.xm.mapper.QuestionsCustomMapper;


public class MybatisTest2 {

    private SqlSessionFactory sqlSessionFactory;

    @Before
    public void setUp() throws Exception {
        // 将全局配置文件作为一个流
        String resource = "sqlMapConfig.xml";
        String realPath = this.getClass().getClassLoader().getResource("sqlMapConfig.xml").getPath();
        InputStream inputStream = Resources.getResourceAsStream(resource);
        // 建立一个SqlSession工厂
        sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
    }
// 测试批量增加
    @Test
    public void testBatchAdd() throws Exception {
        SqlSession sqlSession = sqlSessionFactory.openSession();
        QuestionsCustomMapper qsm = sqlSession.getMapper(QuestionsCustomMapper.class);
        List<Questions> list = new ArrayList<>();
        list.add(new Questions("8", "1", "测试题目8", "", "", "", "", "", "",null, "", ""));
        list.add(new Questions("9", "1", "测试题目8", "", "", "", "", "", "",null, "", ""));
        list.add(new Questions("10", "1", "测试题目8", "", "", "", "", "", "",null, "", ""));
        list.add(new Questions("11", "1", "测试题目8", "", "", "", "", "", "",null, "", ""));
        int total = qsm.saveQuestionBatch(list);
        System.out.println(total);
        sqlSession.commit();
        sqlSession.close();
    }

}

 　　总结:传入单个List上面SQL中collection名字应该是list，输入类型是List

3.批量删除

sql语句:  DELETE FROM `exam`.`questions` WHERE `questionId` IN ('10','11','8','9')

java接口:

/**
     * 批量删除
     * @param ids id集合
     * @return  删除条数
     * @throws Exception
     */
    public int deleteQuestionBatch(List<String> ids)throws Exception; 

mapper.xml

<!-- 批量删除 -->
    <!-- DELETE FROM `exam`.`questions` WHERE `questionId` in ('10','11','8','9') -->
    <delete id="deleteQuestionBatch" parameterType="java.util.List">
        DELETE FROM `exam`.`questions` WHERE `questionId` in 
        <foreach collection="list" item="id" separator="," open="(" close=")">
            #{id}
        </foreach>
    </delete>

测试代码:

package cn.xm.test.mybatis;

import java.io.InputStream;
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.junit.Before;
import org.junit.Test;

import cn.xm.bean.basebean.Questions;
import cn.xm.mapper.QuestionsCustomMapper;

public class MybatisTest2 {

    private SqlSessionFactory sqlSessionFactory;

    @Before
    public void setUp() throws Exception {
        // 将全局配置文件作为一个流
        String resource = "sqlMapConfig.xml";
        String realPath = this.getClass().getClassLoader().getResource("sqlMapConfig.xml").getPath();
        InputStream inputStream = Resources.getResourceAsStream(resource);
        // 建立一个SqlSession工厂
        sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
    }


    // 测试批量删除
    @Test
    public void testBatchDelete() throws Exception {
        SqlSession sqlSession = sqlSessionFactory.openSession();
        QuestionsCustomMapper qsm = sqlSession.getMapper(QuestionsCustomMapper.class);
        List<String> ids = new ArrayList<>();
        ids.add("8");
        ids.add("9");
        ids.add("10");
        ids.add("11");
        int total = qsm.deleteQuestionBatch(ids);
        System.out.println(total);
        sqlSession.commit();
        sqlSession.close();
    }

}

4.  批量更新

需要在db链接url后面带一个参数  &allowMultiQueries=true

spring.datasource.url = jdbc:mysql://localhost:3306/fc?useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true

如下:

接口方法:

void updateUsers(List<User> users);

xml:

  <update id="updateUsers" parameterType="list">
      <foreach collection="list" separator=";" item="item">
        update user  
        <trim prefix="set" suffixOverrides=",">
            <if test="item.phone != null and item.phone != ''">
                phone = #{item.phone},
            </if>
            <if test="item.roles != null and item.roles != ''">
                roles = #{item.roles},
            </if>
        </trim>
        <where>
            <if test="item.id != null and item.id != ''">
                id = #{item.id}
            </if>
        </where>
    </foreach>

生成的SQL如下:

2019-09-12 11:23:32.397 DEBUG 16468 --- [nio-8088-exec-1] c.qs.mapper.user.UserMapper.updateUsers  : ==>  Preparing: update user set phone = ?, roles = ? WHERE id = ? ; update user set phone = ?, roles = ? WHERE id = ? ; update user set phone = ?, roles = ? WHERE id = ? ; update user set phone = ?, roles = ? WHERE id = ? ; update user set phone = ?, roles = ? WHERE id = ? 
2019-09-12 11:23:32.397 DEBUG 16468 --- [nio-8088-exec-1] c.qs.mapper.user.UserMapper.updateUsers  : ==> Parameters: 123123(String), 3(String), 1(Integer), 123123(String), 8(String), 2(Integer), 123123(String), 6(String), 3(Integer), 123123(String), 7(String), 4(Integer), 123123(String), 7(String), 5(Integer)
2019-09-12 11:23:32.613 DEBUG 16468 --- [nio-8088-exec-1] c.qs.mapper.user.UserMapper.updateUsers  : <==    Updates: 1

　　还有第二种case when 语句的批量更新，这种就不通用了。