Mybatis

简介

  • Mybatis是一个半自动的ORM框架
  • ORM（Object Relational Mapping）对象关系映射，将Java的一个对象与数据表中一行记录一一对应

  • ORM框架提供了实体类与数据表的映射关系，通过映射文件的配置，实现对象的持久化存储

    特点

  • 支持自定义SQL、存储过程

  • 对原有的JDBC进行了封装，几乎消除了所有JDBC代码，让开发者只需关注SQL本身
  • 支持XML和注解配置方式自定完成ORM操作，实现结果映射

    部署

  1. 创建MAVEN项目

  2. 添加pom文件中的依赖 ```xml <?xml version=”1.0” encoding=”UTF-8”?> <project xmlns=”http://maven.apache.org/POM/4.0.0“

    1.   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    2.   xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    4.0.0

    org.example Mybatis

    1.0-SNAPSHOT 

    1.  <maven.compiler.source>8</maven.compiler.source>
    2.  <maven.compiler.target>8</maven.compiler.target>

    1.  <!--Mybatis -->
    2.  <dependency>
    3.      <groupId>org.mybatis</groupId>
    4.      <artifactId>mybatis</artifactId>
    5.      <version>3.4.6</version>
    6.  </dependency>
    7.  <!-- mysql驱动 -->
    8.  <dependency>
    9.      <groupId>mysql</groupId>
    10.      <artifactId>mysql-connector-java</artifactId>
    11.      <version>5.1.47</version>
    12.  </dependency>
    13.  <!-- lombok -->
    14.  <dependency>
    15.      <groupId>org.projectlombok</groupId>
    16.      <artifactId>lombok</artifactId>
    17.      <version>1.18.12</version>
    18.      <scope>provided</scope>
    19.  </dependency>
    20.  <!-- junit单元测试 -->
    21.  <dependency>
    22.      <groupId>junit</groupId>
    23.      <artifactId>junit</artifactId>
    24.      <version>4.12</version>
    25.      <scope>test</scope>
    26.  </dependency>
  1. </dependencies>

  2. 3. 添加Mybatis配置文件
  3. ```xml
  4. <?xml version="1.0" encoding="UTF-8" ?>
  5. <!DOCTYPE configuration
  6.         PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
  7.         "http://mybatis.org/dtd/mybatis-3-config.dtd">
  8. <configuration>
  9.     <environments default="development">
  10.         <environment id="development">
  11.             <transactionManager type="JDBC"/>
  12.             <dataSource type="POOLED">
  13.                 <!--数据库连接配置-->
  14.                 <property name="driver" value="com.mysql.jdbc.Driver"/>
  15.                 <property name="url" value="jdbc:mysql://10.30.59.136/wy?serverTimezone=GMT&amp;characterEncoding=UTF-8"/>
  16.                 <property name="username" value="root"/>
  17.                 <property name="password" value="123456"/>
  18.             </dataSource>
  19.         </environment>
  20.     </environments>
  21.     <!--sql映射文件路径-->
  22.     <mappers>
  23.         <mapper resource="mappers/BookMapper"/>
  24.     </mappers>
  25. </configuration>

Mybatis使用

  1. 创建数据表实体类 ```java package pojo;

public class Bookdatabase { public int getId() { return id; }

  1. public void setId(int id) {
  2.     this.id = id;
  3. }
  5. public String getName() {
  6.     return name;
  7. }
  9. public void setName(String name) {
  10.     this.name = name;
  11. }
  13. public int getAge() {
  14.     return age;
  15. }
  17. public void setAge(int age) {
  18.     this.age = age;
  19. }
  20. @Override
  21. public String toString() {
  22.     return "Bookdatabase{" +
  23.             "id=" + id +
  24.             ", name='" + name + '\'' +
  25.             ", age=" + age +
  26.             '}';
  27. }
  28. private int id;
  29. private String name;
  30. private int age;

}

  2. 2. 创建接口类
  3. ```java
  4. package dao;
  6. import pojo.Bookdatabase;
  8. import java.util.List;
  10. public interface Bookdatamap {
  11.     public int insertBook(Bookdatabase book);
  12. }
  1. 创建sql映射文件
    1. <?xml version="1.0" encoding="UTF-8" ?>
    2. <!DOCTYPE mapper
    3.      PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
    4.      "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    5. <!--设置名称空间-->
    6. <mapper namespace="dao.Bookdatamap">
    7.  <!--定义SQL语句,id为绑定的借口类中的方法名-->
    8.  <insert id="insertBook">
    9.      insert into test(id,name,age) values(#{id},#{name},#{age})
    10.  </insert>
    11. </mapper>