MyBatis insert 获取自增主键

深藏阁楼爱情的钟 2022-10-24 14:29 189阅读 0赞

1、建表语句

create table user(
    id int PRIMARY KEY auto_increment,
    name varchar(400)
    );

2、Maven 依赖

<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
    
        <parent>
            <groupId>constxiong</groupId>
            <artifactId>demo</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </parent>
        <artifactId>mybatis-autoincrement</artifactId>
    
        <dependencies>
            
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>8.0.21</version>
            </dependency>
    
            
            <dependency>
    		  <groupId>org.mybatis</groupId>
    		  <artifactId>mybatis</artifactId>
    		  <version>3.5.5</version>
    		</dependency>
    
        </dependencies>
    
        <build>
    
        </build>
    </project>

3、mybatis-config.xml 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">
    <configuration>
        <settings>
            <setting name="logImpl" value="STDOUT_LOGGING"></setting>
        </settings>
        <environments default="development">
            <environment id="development">
                <transactionManager type="JDBC"/>
                <dataSource type="POOLED">
                    <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                    <property name="url" value="jdbc:mysql://172.31.32.184:3306/constxiong?serverTimezone=UTC&useSSL=false&useUnicode=true&characterEncoding=UTF-8"/>
                    <property name="username" value="root"/>
                    <property name="password" value="constxiong@123"/>
                </dataSource>
            </environment>
        </environments>
        <mappers>
            <mapper resource="constxiong/mapper/UserMapper.xml"/>
        </mappers>
    </configuration>

4、Mapper 接口

package constxiong.mapper;
    
    import constxiong.po.User;
    
    /**
     * UserMapper 接口，映射对数据库的操作
     */
    public interface UserMapper {
    
        int insertUser(User user);
    
    }

5、Mapper xml

<?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="constxiong.mapper.UserMapper">
    
        <insert id="insertUser" parameterType="constxiong.po.User" useGeneratedKeys="true" keyProperty="id">
            insert into user(name) values(#{name})
        </insert>
    
    </mapper>

6、User po 模型

package constxiong.po;
    
    /**
     * 用户表模型
     */
    public class User {
        private Integer id;
    
        private String name;
    
        private String mc;
    
        public User(Integer id, String name) {
            this.id = id;
            this.name = name;
        }
    
        public Integer getId() {
            return id;
        }
    
        public void setId(Integer id) {
            this.id = id;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public String getMc() {
            return mc;
        }
    
        public void setMc(String mc) {
            this.mc = mc;
        }
    
        @Override
        public String toString() {
            return "User{" +
                    "id=" + id +
                    ", name='" + name + '\'' +
                    ", mc='" + mc + '\'' +
                    '}';
        }
    }

7、测试类

package constxiong;
    
    import java.io.IOException;
    import java.io.InputStream;
    
    import org.apache.ibatis.io.Resources;
    import org.apache.ibatis.session.SqlSession;
    import org.apache.ibatis.session.SqlSessionFactory;
    import org.apache.ibatis.session.SqlSessionFactoryBuilder;
    
    import constxiong.mapper.UserMapper;
    import constxiong.po.User;
    
    /**
     * 测试 Mybatis 获取自增主键
     */
    public class Test {
    
        public static void main(String[] args) throws IOException {
            testBatchInsert();
        }
    
        /**
         * 测试 xml 配置方式分页
         */
        private static void testBatchInsert() throws IOException {
            String resource = "mybatis-config.xml";//xml配置文件路径
            InputStream inputStream = Resources.getResourceAsStream(resource);//读取配置
            SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);//构建 SqlSessionFactory
            SqlSession sqlSession = sqlSessionFactory.openSession(true);//通过 SqlSessionfactory 获取 SqlSession
    
            UserMapper userMapper = sqlSession.getMapper(UserMapper.class);//通过 SqlSession 获取 Mapper 接口
    
            System.out.println("------userMapper.insertUser()------");
            for (int i = 0; i < 10; i++) {
                User user = new User(null, "constxiong" + i);//这里 user.id = null
                userMapper.insertUser(user);
                System.out.println("id:" + user.getId());//插入数据库后，这里的 user.id 为主键值
            }
    
            //关闭 SqlSession
            sqlSession.close();
        }
    
    }

8、输出

------userMapper.insertUser()------
    Opening JDBC Connection
    Created connection 1048027629.
    ==>  Preparing: insert into user(name) values(?)
    ==> Parameters: constxiong0(String)
    <==    Updates: 1
    id:21
    ==>  Preparing: insert into user(name) values(?)
    ==> Parameters: constxiong1(String)
    <==    Updates: 1
    id:22
    ==>  Preparing: insert into user(name) values(?)
    ==> Parameters: constxiong2(String)
    <==    Updates: 1
    id:23
    ==>  Preparing: insert into user(name) values(?)
    ==> Parameters: constxiong3(String)
    <==    Updates: 1
    id:24
    ==>  Preparing: insert into user(name) values(?)
    ==> Parameters: constxiong4(String)
    <==    Updates: 1
    id:25
    ==>  Preparing: insert into user(name) values(?)
    ==> Parameters: constxiong5(String)
    <==    Updates: 1
    id:26
    ==>  Preparing: insert into user(name) values(?)
    ==> Parameters: constxiong6(String)
    <==    Updates: 1
    id:27
    ==>  Preparing: insert into user(name) values(?)
    ==> Parameters: constxiong7(String)
    <==    Updates: 1
    id:28
    ==>  Preparing: insert into user(name) values(?)
    ==> Parameters: constxiong8(String)
    <==    Updates: 1
    id:29
    ==>  Preparing: insert into user(name) values(?)
    ==> Parameters: constxiong9(String)
    <==    Updates: 1
    id:30
    Closing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@3e77a1ed]
    Returned connection 1048027629 to pool.
    
    Process finished with exit code 0

--------------------

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