mybatis批量增加与删除—

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:

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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。