1. 引入依赖

在pom.xml 引入ORM框架（Mybaits-Starter）和数据库驱动（MySQL-Conn）的依赖

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.6.RELEASE</version>
</parent>

<dependencies>
        <dependency> <!--添加Web依赖 -->
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency> <!--添加Mybatis依赖 -->
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.1</version>
        </dependency>
        <dependency><!--添加MySQL驱动依赖 -->
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency><!--添加Test依赖 -->
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

2添加数据源

spring.datasource.url=jdbc:mysql://127.0.0.1/springboot2?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC&useSSL=true
spring.datasource.username=root
spring.datasource.password=514730
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

spring.jpa.properties.hibernate.hbm2ddl.auto=update
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect
spring.jpa.show-sql= true

spring.thymeleaf.cache=false

#中文
spring.http.encoding.charset=UTF-8
spring.http.encoding.force=true
spring.http.encoding.enabled=true

3. 编写数据层代码

//entity类如下
public class Book {
    private  long id;

    private  String name;

    private  String writer;

    private  String introduction;
    //省略 set get toString

//数据层代码如下:
package com.neo.repository;

import com.neo.entity.Book;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;

import java.util.List;

@Mapper
public interface BookMapper {

   // @Select("select * from book where 1=1")
   @Select("select * from book where 1=1 ")
    List<Book> Book();

    @Select("select * from book where name like '%${name}%'")
    List<Book> findBookByName(@Param("name") String name);
}

4服务处

package com.neo.service.impl;

import com.neo.entity.Book;
import com.neo.repository.BookMapper;
import com.neo.service.BookService;
import org.apache.ibatis.annotations.Param;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
@Service
public class BookServiceImpl implements BookService {
    @SuppressWarnings("all")
    @Autowired
    private BookMapper mapper;


    @Override
    public List<Book> Book() {
        return mapper.Book();
    }

    @Override
    public List<Book> findBookByName(@Param("name")String name) {
        return mapper.findBookByName(name);
    }
}

----------------
package com.neo.service;

import com.neo.entity.User;

import java.util.List;

public interface UserService {

    public List<User> getUserList();

    public User findUserById(long id);

    public void save(User user);

    public void edit(User user);

    public void delete(long id);


}

5. 添加数据库记录

在Navicat 连接本地数据库，随便打开查询窗口，复制下面这段脚本，点击执行即可。

CREATE TABLE book
(
  id           INT AUTO_INCREMENT
    PRIMARY KEY,
  name         VARCHAR(255) NULL,
  writer       VARCHAR(255) NULL,
  introduction VARCHAR(255) NULL
)
  ENGINE = InnoDB;

图片.png

6 controller

package com.neo.web;

import com.neo.entity.Book;
import com.neo.entity.People;
import com.neo.service.BookService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.ModelAndView;
import java.util.*;
@RestController
public class Controller {
 

    @Autowired
    BookService service;
    @GetMapping("book")
    public  List<Book> getBook(){
        return   service.Book();
    }

    @GetMapping("book/{name}")
    public  List<Book> getBook(@PathVariable("name") String name){
        return   service.findBookByName(name);
    }
}

访问
http://localhost:8080/book/
http://localhost:8080/book/三

图片.png 图片.png

https://www.jianshu.com/p/fa89b59ade40

Mybatis like查询的写法

Mybatis like查询官方文档没有明确的例子可循，网上搜索了很多，都不正确。

Mybatis 3.2.6

经过尝试，给出三种可靠可用的写法：

select * from person where name like "%"#{name}"%"

select * from person where name like '%'||#{name}||'%'

select * from person where name like '%${name}%'

三种写法对比后，第一种属于预编译SQL，后两种都不是，因此推荐使用第一种写法。
http://blog.51cto.com/lavasoft/1386870

mybaits错误解决：There is no getter for property named ... in 'class java.lang.String'
也可以在mapper的接口中，给这个方法的参数加上@Param(value=“parentId”)，这样就能在.xml中使用#{parentId} 了。

如：public List<DeptInfo> getDeptInfo(@Param("parentId") String parentId)
https://blog.csdn.net/ybcljay/article/details/80831607