Mybatis实现数据的增删改查实例CRUD

本篇文章主要介绍了Mybatis实现数据的增删改查实例（CRUD），小编觉得挺不错的，现在分享给大家，也给大家做个参考。一起跟随小编过来看看吧

什么是 MyBatis？

MyBatis 是支持普通 sql 查询，存储过程和高级映射的优秀持久层框架。 MyBatis 消除了几乎所有的 JDBC 代码和参数的手工设置以及对结果集的检索。MyBatis 可以使用简单的XML 或注解用于配置和原始映射，将接口和 Java 的 POJO（Plain Old Java Objects，普通的Java对象）映射成数据库中的记录。

MyBatis下载：

Mybatis实例

对一个User表的CRUD操作：

User表：

-- ---------------------------- -- Table structure for `user` -- ---------------------------- DROP TABLE IF EXISTS `user`; CREATE TABLE `user` ( `id` int(11) NOT NULL AUTO_INCREMENT, `userName` varchar(50) DEFAULT NULL, `userAge` int(11) DEFAULT NULL, `userAddress` varchar(200) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8; -- ---------------------------- -- Records of user -- ---------------------------- INSERT INTO `user` VALUES ('1', 'summer', '30', 'shanghai'); INSERT INTO `user` VALUES ('2', 'test2', '22', 'suzhou'); INSERT INTO `user` VALUES ('3', 'test1', '29', 'some place'); INSERT INTO `user` VALUES ('4', 'lu', '28', 'some place'); INSERT INTO `user` VALUES ('5', 'xiaoxun', '27', 'nanjing');

在Src目录下建一个mybatis的xml配置文件Configuration.xml

定义User mappers的User.xml配置文件

select * from `user` where user.id = #{id} select * from user where user.userName = #{userName} insert into user(userName,userAge,userAddress) values(#{userName},#{userAge},#{userAddress}) update user set userName=#{userName},userAge=#{userAge},userAddress=#{userAddress} where id=#{id} delete from user where id=#{id}

配置文件实现了接口和sql语句的映射关系。selectUsersByName采用了2种方式实现，注释掉的也是一种实现，采用resultMap可以把属性和数据库列名映射关系定义好，property为类的属性，column是表的列名，也可以是表列名的别名！

User类的定义：

package com.mybatis.test; public class User { private int id; private String userName; private int userAge; private String userAddress; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getUserName() { return userName; } public void setUserName(String userName) { this.userName = userName; } public int getUserAge() { return userAge; } public void setUserAge(int userAge) { this.userAge = userAge; } public String getUserAddress() { return userAddress; } public void setUserAddress(String userAddress) { this.userAddress = userAddress; } @Override public String toString(){ return this.userName+" "+this.userAge+" "+this.userAddress; } }

IUserOperaton定义：

package com.mybatis.test; import java.util.List; public interface IUserOperation { public User selectUserByID(int id); public List selectUsersByName(String userName); public void addUser(User user); public void updateUser(User user); public void deleteUser(int id); }

IUserOperation为操作接口，函数名和mybatis的xml配置文件中的操作id名对应。

测试类Test：

package com.mybatis.test; import java.io.Reader; import java.util.List; import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.sqlSession; import org.apache.ibatis.session.sqlSessionFactory; import org.apache.ibatis.session.sqlSessionFactoryBuilder; public class Test { private static sqlSessionFactory sqlSessionFactory; private static Reader reader; static { try { reader = Resources.getResourceAsReader("Configuration.xml"); sqlSessionFactory = new sqlSessionFactoryBuilder().build(reader); } catch (Exception e) { e.printstacktrace(); } } public static sqlSessionFactory getSession() { return sqlSessionFactory; } public void getUserByID(int userID) { sqlSession session = sqlSessionFactory.openSession(); try { IUserOperation userOperation = session .getMapper(IUserOperation.class); User user = userOperation.selectUserByID(userID); if (user != null) { System.out.println(user.getId() + ":" + user.getUserName() + ":" + user.getUserAddress()); } } finally { session.close(); } } public void getUserList(String userName) { sqlSession session = sqlSessionFactory.openSession(); try { IUserOperation userOperation = session .getMapper(IUserOperation.class); List users = userOperation.selectUsersByName(userName); for (User user : users) { System.out.println(user.getId() + ":" + user.getUserName() + ":" + user.getUserAddress()); } } finally { session.close(); } } /** * 增加后要commit */ public void addUser() { User user = new User(); user.setUserAddress("place"); user.setUserName("test_add"); user.setUserAge(30); sqlSession session = sqlSessionFactory.openSession(); try { IUserOperation userOperation = session .getMapper(IUserOperation.class); userOperation.addUser(user); session.commit(); System.out.println("新增用户ID：" + user.getId()); } finally { session.close(); } } /** * 修改后要commit */ public void updateUser() { sqlSession session = sqlSessionFactory.openSession(); try { IUserOperation userOperation = session .getMapper(IUserOperation.class); User user = userOperation.selectUserByID(1); if (user != null) { user.setUserAddress("A new place"); userOperation.updateUser(user); session.commit(); } } finally { session.close(); } } /** * 删除后要commit. * * @param id */ public void deleteUser(int id) { sqlSession session = sqlSessionFactory.openSession(); try { IUserOperation userOperation = session .getMapper(IUserOperation.class); userOperation.deleteUser(id); session.commit(); } finally { session.close(); } } public static void main(String[] args) { try { Test test = new test(); // test.getUserByID(1); // test.getUserList("test1"); // test.addUser(); // test.updateUser(); // test.deleteUser(6); } catch (Exception e) { System.out.println(e.getMessage()); } } }

代码下载：MyBaitsSimpleDemo_jb51.rar