MyBatis-Plus的入坑指南

MyBatis-Plus的入坑指南

首先，要使用這玩意，你得需要一個環境，那玩意沒有就可以關閉窗口了

• 擁有 Java 開發環境以及相應 IDE
• 熟悉 Spring Boot
• 熟悉 Maven

然後你需要一張測試的表，我直接拿官網的例子過來

DROP TABLE IF EXISTS user;

CREATE TABLE user
(
	id BIGINT(20) NOT NULL COMMENT '主鍵ID',
	name VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名',
	age INT(11) NULL DEFAULT NULL COMMENT '年齡',
	email VARCHAR(50) NULL DEFAULT NULL COMMENT '郵箱',
	PRIMARY KEY (id)
);


DELETE FROM user;

INSERT INTO user (id, name, age, email) VALUES
(1, 'Jone', 18, '[email protected]'),
(2, 'Jack', 20, '[email protected]'),
(3, 'Tom', 28, '[email protected]'),
(4, 'Sandy', 21, '[email protected]'),
(5, 'Billie', 24, '[email protected]');

數據就和下面這樣

然後你需要生成一個測試工程，推薦用idea的自帶，也可以去spring.io去生成一個，爲了避免有坑，個人建議springboot版本最好是2.2以後的版本

添加依賴

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.2.5.RELEASE</version>
    <relativePath/>
</parent> 

引入jar包（官網裏面是用的H2,我用的MySQL）

         <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.3.1.tmp</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.44</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

配置yml

spring:
  datasource:
    #數據庫url
    url: jdbc:mysql://localhost:3306/demo?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true&serverTimezone=GMT%2B8&useSSL=false
    # 數據庫訪問賬戶
    username: root
    # 數據庫訪問密碼
    password: root123
    driver-class-name: com.mysql.jdbc.Driver

添加mapper掃描

package com.master.mybatiesplus;

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

@SpringBootApplication
@MapperScan("com.master.mybatiesplus.mapper.*")
public class MybatiesPlusApplication {

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

}

編碼

實體類

@Data
public class User {
    private Long id;
    private String name;
    private Integer age;
    private String email;
}

mapper

public interface UserMapper extends BaseMapper<User> {
}

測試類

@RunWith(SpringRunner.class)
@SpringBootTest
public class SampleTest {

    @Autowired
    private UserMapper userMapper;

    @Test
    public void testSelect() {
        System.out.println(("----- selectAll method test ------"));
        List<User> userList = userMapper.selectList(null);
        Assert.assertEquals(5, userList.size());
        userList.forEach(System.out::println);
    }

}

運行測試

User(id=1, name=Jone, age=18, email=[e-mail])
User(id=2, name=Jack, age=20, email=[e-mail])
User(id=3, name=Tom, age=28, email=[e-mail])
User(id=4, name=Sandy, age=21, email=[e-mail])
User(id=5, name=Billie, age=24, email=[e-mail])

小總結

運行到這說明前面的配置和環境都是沒有問題的，接下來進一步操作