


Java implementation of instance method that returns newly added primary key ID
This article mainly introduces the method of MyBatis+MySQL to return the inserted primary key ID. It has certain reference value. Interested friends can refer to it.
Requirement: After using MyBatis to insert a record into the MySQL database, the auto-incremented primary key value of the record needs to be returned.
Method: Specify the keyProperty attribute in mapper. The example is as follows:
<insert id="insertAndGetId" useGeneratedKeys="true" keyProperty="userId" parameterType="com.chenzhou.mybatis.User"> insert into user(userName,password,comment) values(#{userName},#{password},#{comment}) </insert>
As shown above, we specified keyProperty="userId" in insert, where userId represents the inserted User The primary key attribute of object .
User.java
public class User { private int userId; private String userName; private String password; private String comment; //setter and getter }
UserDao.java
public interface UserDao { public int insertAndGetId(User user); }
Test:
User user = new User(); user.setUserName("chenzhou"); user.setPassword("xxxx"); user.setComment("测试插入数据返回主键功能"); System.out.println("插入前主键为:"+user.getUserId()); userDao.insertAndGetId(user);//插入操作 System.out.println("插入后主键为:"+user.getUserId());
Output:
The primary key before insertion is: 0
The primary key after insertion is: 15
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