Mysql > select * from mysqld where mysqld = mybaits

(1) Configure the POM.xml dependency

				<! Add MySql dependency -->
		<dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.11</version>
        </dependency>
        <! Add myBatis dependency -->
        
        <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>2.1.2</version>
        </dependency>
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(2) Configure application.properties

Spring. The datasource. Url = JDBC: mysql: / / 127.0.0.1:3306 / database name is here? CharacterEncoding = utf-8 & useSSL = false&serverTimezone = GMT % 2 b8 spring. The datasource. The username = this is the account Spring. The datasource. Password = password spring here. The datasource. The driver - class - name = com. Mysql. Cj). The JDBC driver mybatis.mapper-locations=classpath:mappering/*.xmlCopy the code

(3) Create entity class

Create entities, Services, and Mapper folders in the Demo folder. Create a Mappering folder under Resources.

Create a new loginUser file in the entities folder:

package com.example.demo.entities;

public class loginUser {
	private String username;
	private int password;
	public String getUsername(a) {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public int getPassword(a) {
		return password;
	}
	public void setPassword(int password) {
		this.password = password;
	}
	public loginUser(a){};
	public loginUser(String name,int pwd) {
		this.password = pwd;
		this.username = name;
	}
	@Override
	public String toString(a) {
		return "User [username=" + username + ", password=" + password + "]"; }}Copy the code

(4) Write the configuration file of mapper

Create userMappling.xml in the Mappering folder

      
<! DOCTYPEmapper PUBLIC "- / / mybatis.org//DTD Mapper / 3.0 / EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.demo.mapper.UserMapper">
    <resultMap id="BaseResultMap" type="com.example.demo.entities.loginUser">
        <result column="id" jdbcType="INTEGER" property="id" />
        <result column="username" jdbcType="VARCHAR" property="username" />
        <result column="password" jdbcType="INTEGER" property="password" />
    </resultMap>
 
    <select id="Sel" resultType="com.example.demo.entities.loginUser">
        select * from User where id = #{id}
    </select>
</mapper>
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(5) Write Mapper mapping files

Create a usermapper.class file in the mapper folder

package com.example.demo.mapper;

import org.springframework.stereotype.Repository;
import com.example.demo.entities.loginUser;
@Repository
public interface UserMapper {
	loginUser Sel(int id);
}
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(6) Write service

Create a UserService folder in the Services folder

package com.example.demo.services;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.example.demo.entities.loginUser;
import com.example.demo.mapper.*;

@Service
public class UserService {
	@Autowired
	UserMapper usermapper;
	public loginUser Sel(int id){
	        returnusermapper.Sel(id); }}Copy the code

(7) Configure the Controller

Open the testController we created earlier. The connection

package com.example.demo.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.example.demo.services.UserService;

@RestController
@RequestMapping("/testBoot")
public class testController {
	 @Autowired
	    private UserService userService;
	
	  @RequestMapping("/hello")
	    public String hello(a) {
	        return "Hello Spring Boot!";
	    }
	  @RequestMapping("/getUser")
	    public String GetUser(a){
		  System.out.print("Here we go.");
	        return userService.Sel(0).toString(); }}Copy the code

(8) Add the DidididiApplication file

package com.example.demo;

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

@SpringBootApplication
@MapperScan("com.example.demo.mapper")
public class DidididiApplication {

	public static void main(String[] args) { SpringApplication.run(DidididiApplication.class, args); }}Copy the code