MyBatisPlus增删改查

第一步：创建Maven项目

添加Maven依赖：

<dependency>
    <groupId>junitgroupId>
    <artifactId>junitartifactId>
    <version>4.12version>
    <scope>testscope>
dependency>

<dependency>
    <groupId>org.projectlombokgroupId>
    <artifactId>lombokartifactId>
    <version>1.18.10version>
dependency>

<dependency>
    <groupId>ch.qos.logbackgroupId>
    <artifactId>logback-classicartifactId>
    <version>1.2.3version>
dependency>

<dependency>
    <groupId>mysqlgroupId>
    <artifactId>mysql-connector-javaartifactId>
    <version>8.0.13version>
dependency>
<dependency>
    <groupId>com.alibabagroupId>
    <artifactId>druidartifactId>
    <version>1.1.12version>
dependency>

<dependency>
    <groupId>org.mybatisgroupId>
    <artifactId>mybatis-typehandlers-jsr310artifactId>
    <version>1.0.2version>
dependency>
<dependency>
    <groupId>com.baomidougroupId>
    <artifactId>mybatis-plusartifactId>
    <version>3.3.0version>
dependency>
<dependency>
    <groupId>com.baomidougroupId>
    <artifactId>mybatis-plus-coreartifactId>
    <version>3.3.0version>
dependency>
<dependency>
    <groupId>com.baomidougroupId>
    <artifactId>mybatis-plus-extensionartifactId>
    <version>3.3.0version>
dependency>
<dependency>
    <groupId>com.baomidougroupId>
    <artifactId>mybatis-plus-annotationartifactId>
    <version>3.3.0version>
dependency>

<dependency>
    <groupId>org.springframeworkgroupId>
    <artifactId>spring-contextartifactId>
    <version>5.2.1.RELEASEversion>
dependency>
<dependency>
    <groupId>org.springframeworkgroupId>
    <artifactId>spring-aopartifactId>
    <version>5.2.1.RELEASEversion>
dependency>
<dependency>
    <groupId>org.springframeworkgroupId>
    <artifactId>spring-jdbcartifactId>
    <version>5.2.1.RELEASEversion>
dependency>
<dependency>
    <groupId>org.springframeworkgroupId>
    <artifactId>spring-testartifactId>
    <version>5.2.1.RELEASEversion>
    <scope>testscope>
dependency>

第二步：在resources目录下编写配置文件

log4j2.xml

<configuration status="error">
    
    <appenders>
        
        <Console name="Console" target="SYSTEM_OUT">
            
            <ThresholdFilter level="trace" onMatch="ACCEPT" onMismatch="DENY"/>
            
            <PatternLayout pattern="%d{HH:mm:ss.SSS} %-5level %class{36} %L %M - %msg%xEx%n"/>
        Console>

        
        <RollingFile name="RollingFile" fileName="logs/web.log"
                     filePattern="logs/$${date:yyyy-MM}/web-%d{MM-dd-yyyy}-%i.log.gz">
            <PatternLayout pattern="%d{yyyy-MM-dd 'at' HH:mm:ss z} %-5level %class{36} %L %M - %msg%xEx%n"/>
            <SizeBasedTriggeringPolicy size="2MB"/>
        RollingFile>
    appenders>

    
    <loggers>
        
        <root level="trace">
            <appender-ref ref="RollingFile"/>
            <appender-ref ref="Console"/>
        root>
    loggers>
configuration>

mysql.properties

driverClass=com.mysql.cj.jdbc.Driver
connectionURL=jdbc:mysql://127.0.0.1/db_test?useSSL=false&serverTimezone=GMT&nullCatalogMeansCurrent=true
userId=root
password=root

mybatis-cfg.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <settings>
        <!-- 不支持缓存 -->
        <setting name="cacheEnabled" value="false"/>
        <!-- 设置等待数据库响应时间，单位秒 -->
        <setting name="defaultStatementTimeout" value="5"/>
        <!-- 允许JDBC支持生成主键 -->
        <setting name="useGeneratedKeys" value="true"/>

        <setting name="logImpl" value="STDOUT_LOGGING"/>   <!-- 打印查询语句 -->
        <setting name="mapUnderscoreToCamelCase" value="true"/><!-- mybatis下划线转驼峰式 -->
    </settings>

    <!-- 别名 -->
    <typeAliases>
        <package name="com.hc.bean"/>
    </typeAliases>

    <!-- 插件配置项 -->
    <plugins>
        <!-- 分页查询插件 -->
        <plugin interceptor="com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor">
            <property name="dialectType" value="mysql"/>
        </plugin>
    </plugins>

</configuration>

mybatisplus.xml

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
   http://www.springframework.org/schema/beans/spring-beans.xsd
   http://www.springframework.org/schema/context
   http://www.springframework.org/schema/context/spring-context.xsd
   http://www.springframework.org/schema/tx
   http://www.springframework.org/schema/tx/spring-tx.xsd">

    
    <context:property-placeholder location="classpath:mysql.properties"/>

    
    <bean id="ds" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${driverClass}">property>
        <property name="url" value="${connectionURL}">property>
        <property name="username" value="${userId}">property>
        <property name="password" value="${password}">property>
        
        <property name="filters" value="stat"/>
    bean>

    
    <bean id="globalConfig" class="com.baomidou.mybatisplus.core.config.GlobalConfig">
        <property name="dbConfig">
            <bean class="com.baomidou.mybatisplus.core.config.GlobalConfig.DbConfig">
                
                <property name="tableUnderline" value="true">property>
                
                <property name="idType" value="AUTO"/>
                
                <property name="tablePrefix" value="tb_"/>
            bean>
        property>
    bean>

    
    <bean id="sqlSessionFactory" class="com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean">
        
        <property name="dataSource" ref="ds"/>
        
        <property name="mapperLocations" value="classpath*:mapper/*.xml"/>
        <property name="configLocation" value="classpath:mybatisplus-cfg.xml"/>
        
        <property name="globalConfig" ref="globalConfig">property>
    bean>

    
    
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        
        <property name="basePackage" value="com.hc.dao"/>
        
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
    bean>

    
    <bean id="txManager"
          class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="ds"/>
    bean>
    
    <tx:annotation-driven transaction-manager="txManager"/>
beans>

spring.xml

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
   http://www.springframework.org/schema/beans/spring-beans.xsd
   http://www.springframework.org/schema/context
   http://www.springframework.org/schema/context/spring-context.xsd">

    <context:component-scan base-package="com.hc"/>
    <import resource="mybatisplus.xml"/>

beans>

第三步：创建实体类

@Getter
@Setter
@ToString
@Builder
@AllArgsConstructor
@NoArgsConstructor
@TableName(value = "db_test.tb_emp")
public class Emp extends Model<Emp> implements Serializable {  //继承Model类，是为了实现AR功能
    
    private static final long serialVersionUID = -1696472017703928733L;

    @TableId(value = "empno", type = IdType.INPUT)
    private Integer empno;

    @TableField(value = "ename")
    private String ename;

    @TableField(value = "job")
    private String job;

    @TableField(value = "mgr")
    private Integer mgr;

    @TableField(value = "hiredate")
    private LocalDate hiredate;

    @TableField(value = "sal")
    private BigDecimal sal;

    @TableField(value = "comm")
    private BigDecimal comm;

    @TableField(value = "deptno")
    private Integer deptno;

}

第四步：创建Dao文件

public interface EmpMapper extends BaseMapper<Emp> {
}

第五步：创建映射文件

<mapper namespace="com.hc.dao.EmpMapper">
    <resultMap id="BaseResultMap" type="com.hc.bean.Emp">
        <id column="empno" property="empno"/>
        <result column="ename" property="ename"/>
        <result column="job" property="job"/>
        <result column="mgr" property="mgr"/>
        <result column="hiredate" property="hiredate"/>
        <result column="sal" property="sal"/>
        <result column="comm" property="comm"/>
        <result column="deptno" property="deptno"/>
    resultMap>

    <sql id="Base_Column_List">
        empno, ename, job, mgr, hiredate, sal, comm, deptno
    sql>
mapper>

第六步：Mapper测试

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration({"classpath:mybatisplus.xml"})
public class EmpDaoMapperTest {

    @Autowired
    private EmpMapper empMapper;

    @Test
    public void insert() {
        Emp emp = new Emp(1234, "zhangsan", "CLERK", 7788, LocalDate.of(1999, 9, 21), new BigDecimal(1200), new BigDecimal(300), 20);
        int insertRes = empMapper.insert(emp);
        System.out.println(insertRes);
        System.out.println(emp.getEmpno());//直接获取插入数据返回的自增主键值
    }

    @Test
    public void insert1() {
        Emp emp = new Emp(1234, "zhangsan", "CLERK", 7788, LocalDate.of(1999, 9, 21), new BigDecimal(1200), new BigDecimal(300), 20);
        empMapper.insert(emp);
        emp = new Emp(1235, "zhangsan", "CLERK", 7788, LocalDate.of(1999, 9, 21), new BigDecimal(1200), new BigDecimal(300), 20);
        empMapper.insert(emp);
        emp = new Emp(1236, "zhangsan", "CLERK", 7788, LocalDate.of(1999, 9, 21), new BigDecimal(1200), new BigDecimal(300), 20);
        empMapper.insert(emp);
        emp = new Emp(1237, "zhangsan", "CLERK", 7788, LocalDate.of(1999, 9, 21), new BigDecimal(1200), new BigDecimal(300), 20);
        empMapper.insert(emp);
        emp = new Emp(1238, "zhangsan", "CLERK", 7788, LocalDate.of(1999, 9, 21), new BigDecimal(1200), new BigDecimal(300), 20);
        empMapper.insert(emp);
        emp = new Emp(1239, "zhangsan", "CLERK", 7788, LocalDate.of(1999, 9, 21), new BigDecimal(1200), new BigDecimal(300), 20);
        empMapper.insert(emp);

    }

    @Test
    public void update() {
        Emp emp = new Emp(1235, "张三", "SALES", 7698, LocalDate.of(2018, 9, 21), new BigDecimal(1300), new BigDecimal(400), 20);
        int updateRes = empMapper.updateById(emp);
        System.out.println(updateRes);
    }


    @Test
    public void delete1() {
        int deleteRes = empMapper.deleteById(1235);
        System.out.println(deleteRes);
    }

    @Test
    public void delete2() {
        QueryWrapper<Emp> queryWrapper = new QueryWrapper<>();
        queryWrapper.eq("ename", "张三");
        int deleteRes = empMapper.delete(queryWrapper);
        System.out.println(deleteRes);
    }

    @Test
    public void delete3() {
        int deleteRes = empMapper.deleteBatchIds(Arrays.asList(1236, 1237));
        System.out.println(deleteRes);
    }

    @Test
    public void delete4() {
        Map<String, Object> map = new HashMap<>();
        map.put("ename", "zhangsan");
        int deleteRes = empMapper.deleteByMap(map);
        System.out.println(deleteRes);
    }

    @Test
    public void select1() {
        Emp emp = empMapper.selectById(7788);
        System.out.println(emp);
    }

    @Test
    public void select2() {
        QueryWrapper<Emp> queryWrapper = new QueryWrapper<>();
        queryWrapper.eq("ename", "scott");
        queryWrapper.eq("deptno", "20");
        Emp emp = empMapper.selectOne(queryWrapper);
        System.out.println(emp);
    }

    @Test
    public void select3() {
        QueryWrapper<Emp> queryWrapper = new QueryWrapper<>();
        queryWrapper.like("ename", "%AR%");
        List<Emp> empList = empMapper.selectList(queryWrapper);
        for (Emp emp : empList) {
            System.out.println(emp);
        }
    }

    @Test
    public void select4() {
        List<Emp> empList = empMapper.selectBatchIds(Arrays.asList(7369, 7782, 7844));
        for (Emp emp : empList) {
            System.out.println(emp);
        }
    }

    @Test
    public void select5() {
        Map<String, Object> map = new HashMap<>();
        map.put("ename", "zhangsan");
        map.put("job", "clerk");
        List<Emp> empList = empMapper.selectByMap(map);
        for (Emp emp : empList) {
            System.out.println(emp);
        }
    }

    @Test
    public void select6() {
        IPage<Emp> empPage = empMapper.selectPage(new Page<>(2, 2), null);
        for (Emp emp : empPage.getRecords()) {
            System.out.println(emp);
        }
    }

    @Test
    public void select7() {
        Wrapper<Emp> queryWrapper = new QueryWrapper<Emp>()
                .between("sal", 1500, 3500)
                .like("ename", "%A%");
        IPage<Emp> empPage = empMapper.selectPage(new Page<>(1, 3), queryWrapper);
        for (Emp emp : empPage.getRecords()) {
            System.out.println(emp);
        }
    }
    
}

第七步：AR测试

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration({"classpath:mybatisplus.xml"})
public class EmpDaoARTest {

    @Test
    public void insert(){
        Emp emp = new Emp(1230,"zhangsan","CLERK",7788, LocalDate.of(1999,9,21),new BigDecimal(1200),new BigDecimal(300),20);
        boolean insertRes = emp.insert( );
        System.out.println(insertRes);
        System.out.println(emp.getEmpno());//直接获取插入数据返回的自增主键值
    }

    @Test
    public void update(){
        Emp emp = new Emp(1230,"张三","SALES",7521, LocalDate.of(2018,9,21),new BigDecimal(1400),new BigDecimal(400),10);
        boolean updateRes = emp.updateById();
        System.out.println(updateRes);
    }

    @Test
    public void delete1(){
        Emp emp = new Emp();
        boolean deleteRes1 = emp.deleteById(1230);
        System.out.println(deleteRes1);

        emp.setEmpno(1234);
        boolean deleteRes2 = emp.deleteById();
        System.out.println(deleteRes2);
    }

    @Test
    public void delete2(){
        Emp emp = new Emp();
        QueryWrapper<Emp> queryWrapper =new QueryWrapper<>();
        queryWrapper.ge("empno",7902);
        boolean res = emp.delete(queryWrapper);
        System.out.println(res);
    }


    @Test
    public void select1(){
        Emp emp = new Emp();
        Emp emp1 = emp.selectById(7788);
        System.out.println(emp1);

        emp.setEmpno(7788);
        Emp emp2 = emp.selectById();
        System.out.println(emp2);
    }

    @Test
    public void select2(){
        List<Emp> empList = new Emp().selectAll();
        for (Emp item : empList) {
            System.out.println(item);
        }
    }

    @Test
    public void select3(){
        QueryWrapper<Emp> queryWrapper = new QueryWrapper<Emp>().like("ename","%SCOTT%");
        Emp emp = new Emp();
        List<Emp> empList = emp.selectList(queryWrapper);
        for (Emp item : empList) {
            System.out.println(item);
        }
        Integer count = emp.selectCount(queryWrapper);//参数值为null时表示查看全表
        System.out.println(count);
    }

    @Test
    public void select4(){
        Wrapper<Emp> queryWrapper = new QueryWrapper<Emp>().lt("sal",1500);
        IPage<Emp> empPage = new Emp().selectPage(new Page<>(2, 2), queryWrapper);
        for (Emp emp :empPage.getRecords()){
            System.out.println(emp);
        }
        System.out.println(empPage.getTotal());
        System.out.println(empPage.getCurrent());
        System.out.println(empPage.getPages());
        System.out.println(empPage.getSize());
        System.out.println(empPage.offset());
    }

}