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Java implementation of instance method that returns newly added primary key ID
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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