2. 概述

MyBatis-Plus 是一个 Mybatis 的增强工具，在 Mybatis的基础上只做增强不做修改。

在本章中详细说明了 KingbaseES 对 MyBatis-Plus的支持情况，以及使用时应该注意的问题。

3. MyBatis-Plus配置说明

Mybatis-Plus的jar包可以从官方网站下载，Mybatis-Plus所使用的JDBC包kingbase8-8.6.0.jar位于$KINGBASE_HOME/Interface/jdbc目录下。使用时将Mybatis-Plus包和JDBC包导入到项目的Libraries中并定义相关配置项即可。

定义Mybatis-Plus配置文件，根据用户选择，更改一下配置文件。以SpringMVC工程整合Mybatis-Plus3.x为例：

1. 配置spring配置文件：

配置MapperScan：

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

调整SqlSessionFactory为Mybatis-Plus的SqlSessionFactory：

<bean id="sqlSessionFactory" class="com.baomidou.mybatisplus.extension
.spring.MybatisSqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="typeAliasesPackage" value="com.baomidou.mybatisplus
    .Mybatis_plus_Sample.entity" />
    <property name="plugins">
        <array>
            <!-- 分页插件配置 -->
            <bean id="paginationInterceptor"
                class="com.baomidou.mybatisplus.extension.plugins
                .PaginationInterceptor">
                <property name="dialectType" value="postgresql" />
            </bean>
        </array>
    </property>
</bean>

1. 配置实体类：

@TableName(value = "tb_employee") /* 指定表名 */
public class Employee {
    /*  value与数据库主键列名一致，若实体类属性名与表主键列名一致可省略value */
    @TableId(value = "id", type = IdType.AUTO) /* 指定自增策略 */
    private Integer id;
    /*  若没有开启驼峰命名，或者表中列名不符合驼峰规则，可通过该注解 */
    /*  指定数据库表中的列名，exist标明数据表中有没有对应列 */
    @TableField(value = "last_name", exist = true)
    private String lastName;
    private String email;
    private boolean gender;
    private Integer age;
    private Date date;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public boolean isGender() {
        return gender;
    }

    public void setGender(boolean gender) {
        this.gender = gender;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }

    @Override
    public String toString() {
        return "Employee [id=" + id + ", lastName=" + lastName + ",
        email=" + email + ", gender=" + gender +", age=" + age + ",
        date=" + date + "]";
    }
}

1. 定义Mapper接口：

@Mapper
public interface EmplopyeeDao extends BaseMapper {
}

1. 在Java中进行表的增删改查操作：

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration({ "classpath:spring/spring-dao.xml" })
public class test {
    @Autowired
    private DataSource dataSource;

    @Test
    public void testDataSource() throws SQLException {
        System.out.println(dataSource.getConnection());
    }

    @Autowired
    private EmplopyeeDao emplopyeeDao;

    @Test
    public void testInsert() {
        Employee employee = new Employee();
        employee.setLastName("tom");
        employee.setEmail("dfbb@163.com");
        employee.setGender(false);
        employee.setAge(22);
        employee.setDate(new Date(System.currentTimeMillis()));
        emplopyeeDao.insert(employee);
        /*  mybatisplus会自动把当前插入对象在数据库中的id写回到该实体中 */
        System.out.println(employee.getId());
    }

    @Test
    public void testUpdate() {
        Employee employee = new Employee();
        employee.setId(1);
        employee.setLastName("更新测试");
        /* 根据id进行更新，没有传值的属性就不会更新 */
        emplopyeeDao.updateById(employee);
        /* 根据id进行更新，没传值的属性就更新为null */
        emplopyeeDao.update(employee, null);
    }

    @Test
    public void testSelectById() {
        Employee employee = emplopyeeDao.selectById(2);
        System.out.println(employee.toString());
    }

    @Test
    public void testSelect() {
        Map columnMap = new HashMap();
        /* 写表中的列名 */
        columnMap.put("last_name", "更新测试");
        columnMap.put("gender", false);
        List employees = emplopyeeDao.selectByMap(columnMap);
        System.out.println(employees.size());
    }

    @Test
    public void testSelectByPage() {
        IPage employees = emplopyeeDao.selectPage(new Page(1, 5),
                new QueryWrapper().between("age", 18, 50).eq("gender",
                false).eq("last_name", "更新测试"));
        System.out.println(employees);
    }

    @Test
    public void testDeleteById() {
        System.out.println(emplopyeeDao.deleteById(1));
    }

    @Test
    public void testDelete() {
        Map columnMap = new HashMap();
        columnMap.put("gender", false);
        columnMap.put("age", 18);
        emplopyeeDao.deleteByMap(columnMap);
    }

    @Test
    public void testSelectByPage1() {
        Integer[] ints = { 1, 18, 19, 20, 21, 22, 23, 24, 25 };
        IPage employees = emplopyeeDao.selectPage(new Page(1, 5),
                new QueryWrapper().between("age", 18, 50).eq("gender",
                false).eq("last_name", "更新测试").in(true,
                        "age", Arrays.asList(ints)));
        System.out.println(employees.toString());
        System.out.println(employees.getTotal());
        System.out.println(employees.getPages());
        System.out.println(employees.getRecords());
    }
}