tkMapper插件的详细讲解

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一、tkMapper简介

tkMapper就是一个MyBatis插件，是在MyBatis的基础上提供的开发工具，可以让开发变得简单，提高开发效率。

作用：

1、提供了针对单表通用的数据库操作方法

2、逆向工程（根据数据表生成实体类、dao接口、映射文件）

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二、tkMapper整合

1、基于SpringBoot完成MyBatis的整合

2、整合tkMapper

2.1、添加tkMapper的依赖

       <dependency>
            <groupId>tk.mybatis</groupId>
            <artifactId>mapper-spring-boot-starter</artifactId>
            <version>2.1.5</version>
        </dependency>

2.2、修改启动类的@MapperScan注解的包为tk.mybatis.spring.annotation.MapperScan

package com.qfedu.tkmapperdemo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import tk.mybatis.spring.annotation.MapperScan;

@SpringBootApplication
@MapperScan("com.qfedu.tkmapperdemo.dao")
public class TkmapperDemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(TkmapperDemoApplication.class, args);
    }

}

三、tkMapper的使用

1、创建数据表

DROP TABLE IF EXISTS `users`;
CREATE TABLE `users` (
  `user_id` int(64) NOT NULL AUTO_INCREMENT COMMENT '主键id;用户id',
  `username` varchar(255) NOT NULL COMMENT '用户名;用户名',
  `password` varchar(64) NOT NULL COMMENT '密码;密码',
  `nickname` varchar(255) DEFAULT NULL COMMENT '昵称;昵称',
  `realname` varchar(90) DEFAULT NULL COMMENT '真实姓名;真实姓名',
  `user_img` varchar(1024) NOT NULL COMMENT '头像;头像',
  `user_mobile` varchar(255) DEFAULT NULL COMMENT '手机号;手机号',
  `user_email` varchar(255) DEFAULT NULL COMMENT '邮箱地址;邮箱地址',
  `user_sex` varchar(1) DEFAULT NULL COMMENT '性别;M(男) or F(女)',
  `user_birth` datetime DEFAULT NULL COMMENT '生日;生日',
  `user_regtime` datetime NOT NULL COMMENT '注册时间;创建时间',
  `user_modtime` datetime NOT NULL COMMENT '更新时间;更新时间',
  PRIMARY KEY (`user_id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8 COMMENT='用户';

2、创建实体类

@Data
@NoArgsConstructor
@AllArgsConstructor
public class User {

    private int userId;
    private String username;
    private String password;
    private String nickname;
    private String realname;
    private String userImg;
    private String userMobile;
    private String userEmail;
    private String userSex;
    private Date userBirth;
    private Date userRegtime;
    private Date userModtime;
}

3、创建DAO接口

tkMapper已经完成了对单表的通用操作的封装，封装在Mapper接口和MySqlMapper接口；因此如果我们要完成对单表的操作，只需自定义DAO接口继承Mapper接口和MySqlMapper接口。

public interface UserDao extends Mapper<User>, MySqlMapper<User> {
}

4、测试

@RunWith(SpringRunner.class)
@SpringBootTest(classes = TkmapperDemoApplication.class)
public class UserDaoTest {

    @Autowired
    private UserDao userDao;

    @Test
    public void test(){
        User user = new User();
        user.setUsername("aaaa");
        user.setPassword("1111");
        user.setUserImg("img/default.png");
        user.setUserRegtime(new Date());
        user.setUserModtime(new Date());
        int i = userDao.insert(user);
        System.out.println(i);
    }

}

四、tkMapper提供的常用方法

@RunWith(SpringRunner.class)
@SpringBootTest(classes = TkmapperDemoApplication.class)
public class CategoryDAOTest {
    @Autowired
    private CategoryDAO categoryDAO;

    @Test
    public void testInsert() {
        Category category = new Category(0, "测试类别2", 1, 0, "0.2png", "haha", "aaa.jpg", "black");
        //int i = categoryDAO.insert(category);
        int i = categoryDAO.insertUseGeneratedKeys(category);
        System.out.println(category.getCategoryId());
        assertEquals(1, i);
    }


    @Test
    public void testUpdate() {
        Category category = new Category(47, "测试类别3", 1, 0, "0.3png", "haha3", "aaa.jpg", "black");
        int i = categoryDAO.updateByPrimaryKey(category);
        //根据自定义条件修改，Example example就是封装条件的
        //categoryDAO.updateByExample(Example example);
        assertEquals(1, i);
    }


    @Test
    public void testDelete(){
        int i = categoryDAO.deleteByPrimaryKey(47);
        //根据条件删除
        //categoryDAO.deleteByExample(Example example);
        assertEquals(1,i);
    }


    @Test
    public void testSelect1(){
        //查询所有
        List<Category> categories = categoryDAO.selectAll();
        for(Category category : categories){
            System.out.println(category);
        }
    }


    @Test
    public void testSelect2(){
        //根据主键查询
        Category category = categoryDAO.selectByPrimaryKey(46);
        System.out.println(category);
    }


    @Test
    public void testSelect3(){
        //条件查询
        //1.创建一个Example封装  类别Category查询条件
        Example example = new Example(Category.class);
        Example.Criteria criteria = example.createCriteria();
        criteria.andEqualTo("categoryLevel",1);
        criteria.orLike("categoryName","%干%");

        List<Category> categories = categoryDAO.selectByExample(example);
        for (Category category : categories){
            System.out.println(category);
        }
    }


    @Test
    public void testSelect4(){
        //分页查询
        int pageNum = 2;
        int pageSize = 10;
        int start = (pageNum-1)*pageSize;

        RowBounds rowBounds = new RowBounds(start, pageSize);
        List<Category> categories = categoryDAO.selectByRowBounds(new Category(), rowBounds);
        for (Category category : categories){
            System.out.println(category);
        }

        //查询总记录数
        int i = categoryDAO.selectCount(new Category());
        System.out.println(i);
    }


    @Test
    public void testSelect5(){
        //带条件分页查询
        //条件
        Example example = new Example(Category.class);
        Example.Criteria criteria = example.createCriteria();
        criteria.andEqualTo("categoryLevel",1);
        //分页
        int pageNum = 2;
        int pageSize = 6;
        int start = (pageNum-1)*pageSize;
        RowBounds rowBounds = new RowBounds(start, pageSize);

        List<Category> categories = categoryDAO.selectByExampleAndRowBounds(example, rowBounds);
        for (Category category:categories){
            System.out.println(category);
        }

        //查询满足条件的总记录数
        int i = categoryDAO.selectCountByExample(example);
        System.out.println(i);

    }
}

五、如何使用tkMapper进行关联查询

所有的关联查询都可以通过多个单表操作实现

    @Test
    public void testSelect(){
        //查询用户的同时查询订单
        Example example = new Example(User.class);
        Example.Criteria criteria = example.createCriteria();
        criteria.andEqualTo("username","zhangsan");
        //根据用户名查询用户
        //1.先根据用户名查询用户信息
        List<User> users = userDao.selectByExample(example);
        User user = users.get(0);
        //2.再根据用户id到订单表查询订单
        Example example1 = new Example(Orders.class);
        Example.Criteria criteria1 = example1.createCriteria();
        criteria1.andEqualTo("userId",user.getUserId());
        List<Orders> ordersList = orderDAO.selectByExample(example1);
        //3.将查询到订单集合设置到user
        user.setOrdersList(ordersList);
        System.out.println(user);
    }

也可自定义连接查询，在DAO接口中自定义方法，创建Mapper文件

六、逆向工程

逆向工程，根据创建好的数据表，生成实体类、DAO、映射文件

1、添加逆向工程依赖

此依赖是一个mybatis的maven插件

            <plugin>
                <groupId>org.mybatis.generatorgroupId>
                <artifactId>mybatis-generator-maven-pluginartifactId>
                <version>1.3.5version>

                <dependencies>
                    <dependency>
                        <groupId>mysqlgroupId>
                        <artifactId>mysql-connector-javaartifactId>
                        <version>5.1.47version>
                    dependency>
                    <dependency>
                        <groupId>tk.mybatisgroupId>
                        <artifactId>mapperartifactId>
                        <version>3.4.4version>
                    dependency>
                dependencies>
            plugin>

2、逆向工程配置

• 在resources/generator目录下创建generatorConfig.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
        PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">

<generatorConfiguration>

    <!--引入数据库连接配置-->


    <context id="Mysql" targetRuntime="MyBatis3Simple" defaultModelType="flat">
        <property name="beginningDelimiter" value="`"/>
        <property name="endingDelimiter" value="`"/>
        <property name="javaFileEncoding" value="UTF-8"/>

        <!--配置 GeneralDAO-->
        <plugin type="tk.mybatis.mapper.generator.MapperPlugin">
            <property name="mappers" value="com.qfedu.tkmapperdemo.general.GeneralDAO"/>
        </plugin>

        <!--配置数据库连接-->
        <jdbcConnection
                driverClass="com.mysql.jdbc.Driver"
                connectionURL="jdbc:mysql://localhost:3306/fmmall"
                userId="root"
                password="mysql">
        </jdbcConnection>

        <!--配置实体类存放路径-->
        <javaModelGenerator targetPackage="com.qfedu.tkmapperdemo.beans" targetProject="src/main/java"/>

        <!--配置 XML 存放路径-->
        <sqlMapGenerator targetPackage="/" targetProject="src/main/resources/mappers"/>

        <!--配置 DAO 存放路径-->
        <javaClientGenerator targetPackage="com.qfedu.tkmapperdemo.dao" targetProject="src/main/java" type="XMLMAPPER"/>

        <table tableName="%">
            <!--mysql 配置-->
            <!--<generatedKey column="id" sqlStatement="Mysql" identity="true"/>-->
            <!--oracle 配置-->
            <!--<generatedKey column="id" sqlStatement="select SEQ_{1}.nextval from dual" identity="false" type="pre"/>-->
        </table>
    </context>
</generatorConfiguration>

3、将配置文件设置到逆向工程的maven插件