SpringMVC-08-Mybatis层编写

Mybatis层编写

1. 数据库配置文件 database.properties

driver=com.mysql.jdbc.Driver
#如果使用的是mysql 8.0+ 需要增加一个时区的配置 &serverTimezone=Asia/Shanghai
url=jdbc:mysql://localhost:3306/mybatis?useSSL=true&useUnicode=true&characterEncoding=UTF-8
username=huba
password=123456

2. IDEA关联数据库

3. 编写Mybatis核心配置文件

   <?xml version="1.0" encoding="UTF-8" ?>
   <!DOCTYPE configuration
           PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
           "http://mybatis.org/dtd/mybatis-3-config.dtd">
   <!--核心配置文件-->
   <configuration>
       <!--配置数据源，现在交给Spring完成-->
   
       <!--别名-->
       <typeAliases>
           <package name="com.kuang.pojo"/>
       </typeAliases>
   
       <!--设置-->
   
       <!--绑定mapper-->
       <mappers>
           <mapper class="com.kuang.dao.BookMapper"/>
       </mappers>
   </configuration>
   

4. 实体类 Books

   使用lombok!

   @Data
   @AllArgsConstructor
   @NoArgsConstructor
   public class Books {
       private int bookID;
       private String bookName;
       private int bookCounts;
       private String detail;
   }
   

5. dao层 BookMapper接口和BookMapper.xml

   public interface BookMapper {
       //增加一本书
       int addBook(Books books);
   
       //删除一本书
       int deleteBookById(@Param("bookId") int id);
   
       //更新一本书
       int updateBook(Books books);
   
       //查询一本书
       Books queryBookById(@Param("bookID") int id);
   
       //查询全部的书
       List<Books> queryAllBook();
   }
   

   <?xml version="1.0" encoding="UTF-8" ?>
   <!DOCTYPE mapper
           PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
           "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
   <mapper namespace="com.kuang.dao.BookMapper">
       <insert id="addBook" parameterType="Books">
           insert into ssmbuild.books (bookName, bookCounts, detail)
           values (#{bookName},#{bookCounts},#{detail});
       </insert>
   
       <delete id="deleteBookById" parameterType="int">
           delete from ssmbuild.books where bookID=#{bookId}
       </delete>
   
       <update id="updateBook" parameterType="Books">
           update ssmbuild.books
           set bookName = #{bookName},bookCounts=#{bookCounts},detail=#{detail}
           where bookID=#{bookID};
       </update>
   
       <select id="queryBookById" resultType="Books">
           select * from ssmbuild.books
           where bookID=#{bookID}
       </select>
   
       <select id="queryAllBook" resultType="Books">
           select * from ssmbuild.books
       </select>
   </mapper>
   

   在mybatis核心配置文件中绑定mapper

   <!--绑定mapper-->
   <mappers>
       <mapper class="com.kuang.dao.BookMapper"/>
   </mappers>
   

6. service层 BookService接口和BookServiceImpl

   public interface BookService {
       //增加一本书
       int addBook(Books books);
   
       //删除一本书
       int deleteBookById(int id);
   
       //更新一本书
       int updateBook(Books books);
   
       //查询一本书
       Books queryBookById(int id);
   
       //查询全部的书
       List<Books> queryAllBook();
   
   }
   

   public class BookServiceImpl implements BookService{
   
       private BookMapper bookMapper;
   
       public void setBookMapper(BookMapper bookMapper) {
           this.bookMapper = bookMapper;
       }
   
       //serice层调用dao层
       public int addBook(Books books) {
           return bookMapper.addBook(books);
       }
   
       public int deleteBookById(int id) {
           return bookMapper.deleteBookById(id);
       }
   
       public int updateBook(Books books) {
           return bookMapper.updateBook(books);
       }
   
       public Books queryBookById(int id) {
           return bookMapper.queryBookById(id);
       }
   
       public List<Books> queryAllBook() {
           return bookMapper.queryAllBook();
       }
   }