springboot+mybatis 第二波实现含xml 和注解实现

数据库

User

package com.entity;

import lombok.Data;
import lombok.Getter;
import lombok.Setter;
import org.springframework.stereotype.Repository;

@Data
public class User {
    private int id;
    private String message;
}

UserMapper

package com.mapper;

import com.entity.User;
import org.apache.ibatis.annotations.*;
import org.springframework.stereotype.Repository;

import java.sql.SQLException;
import java.util.List;

public interface UserMapper {

    @Select("select * from user where message = #{id}")
    List<User> getUserById2(long id);


    //    #单条查询
    @Select("select * from user where id = #{id}")
    User getUserById(long id);

    @Insert("insert into user(Message) values(#{id},#{message})")
//    @Options(keyProperty = "id" , useGeneratedKeys = true)
    public int insterUser(User user);

    @Delete("delete from user where id = #{id}")
    void delStudentById(Integer id);


}

Mybatis720Application

package com;

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

@SpringBootApplication
@MapperScan("com.mapper")
public class Mybatis720Application {

    public static void main(String[] args) {
        SpringApplication.run(Mybatis720Application.class, args);
    }

}

application.yml

（如果要用xml方法写sql 记得把

mybatis:的xml配置放开，并且写到

mybatis:下面(下面还有个 mybatis:

)--用mp时发现的问题

）

## 应用名称
#spring.application.name=Mybatis_7_20
#下面这些内容是为了让MyBatis映射
#指定Mybatis的Mapper文件
mybatis:
  mapper-locations: classpath:mappers/*xml
#指定Mybatis的实体目录
  type-aliases-package: com.entity
# 数据库驱动：
spring:
  aop:
    proxy-target-class: true
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
# 数据源名称
    name: defaultDataSource
# 数据库连接地址
    url: jdbc:mysql://localhost:3306/datademo?serverTimezone=UTC
# 数据库用户名&密码：
    username: root
    password: 669988
# 应用服务 WEB 访问端口
server:
  port: 8180

UserMapperTest.java (单元测试)

package com.mapper;

import com.entity.User;

import net.minidev.json.JSONArray;
import net.minidev.json.JSONObject;
import org.apache.ibatis.session.SqlSession;
import org.apache.logging.log4j.message.Message;
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import sun.font.CompositeFont;
import org.apache.ibatis.session.SqlSessionFactory;

import java.sql.SQLException;
import java.util.List;


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

    @Autowired
    private UserMapper userMapper;
//    @Autowired
//    private User user;

    @Test
    public void getUserById() throws SQLException {
//       单条 查询
//        User user = userMapper.getUserById(1);
//        System.out.println(user.getId());


////      多条 查询
//        List<User> user = userMapper.getUserById2(123);
//        System.out.println(user);



//        新增
//        User user = new User();
//        user.setId(14);
//        user.setMessage("我是1");
//        userMapper.insterUser(user);

////      删除
//        userMapper.delStudentById(12);



    }

}

pom.xml:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.example</groupId>
    <artifactId>Mybatis_7_20</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>Mybatis_7_20</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <spring-boot.version>2.3.7.RELEASE</spring-boot.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- druid连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.0.9</version>
        </dependency>
        <!-- lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.4</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.3.7.RELEASE</version>
                <configuration>
                    <mainClass>com.Mybatis720Application</mainClass>
                </configuration>
                <executions>
                    <execution>
                        <id>repackage</id>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>

单元测试快捷创建的方法:

https://blog.csdn.net/u012430402/article/details/103788721

参考文档: https://blog.csdn.net/u012430402/article/details/104580393

使用xml文件查sql的话

要建xml文件

springboot+mybatis 第二波实现含xml 和注解实现

User.xml

注意: 如果传的参数是表名的话用 ${table} 意思是不要按字符传

注意: 一个xml文件对应一个接口类，下面 namespace="com.mapper.UserMapper" 就是指定接口层是哪个

parameterType为传入的参数类型

resultType  为返回的参数类型

<?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">

<mapper namespace="com.mapper.UserMapper">
　　<!-- 这里是作为一个变量使用 --> <sql id="table">person</sql>


    <!-- id要与接口中方法名保持一致,入参要入接口方法中入参类型保持一致，返回值要与实体类对应
    （一下这种方式要求表中的字段按驼峰命名规则转换后要与实体类中属性名称保持一致） -->
    <select >
    select * from user where id = #{id}
    </select>

<!--    增加-->
<!--    <insert >-->
    <insert  >
        insert into user(id,Message) values(#{id},#{message})
    </insert>
<!--    https://www.cnblogs.com/zhouricong/p/9483099.html-->

 <select >
    select * from 
<include refid="table" />  拿到上面的变量使用
 where id = #{id}
    </select>

</mapper>

UserMapper文件就可以不用写注解了

springboot+mybatis 第二波实现含xml 和注解实现

xml另外一篇实战 https://www.cnblogs.com/kaibindirver/p/15240918.html

参考文档: https://blog.csdn.net/u012430402/article/details/105011363