第三章：注解实现常用的 CRUD-Mybatis合辑5-注解、扩展、SQL构建

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- User.java

```
package com.sunxiaping.domain;

import java.io.Serializable;
import java.util.Date;

public class User implements Serializable {

private Integer id;

private String username;

private Date birthday;

private String gender;

private String address;

public Integer getId() {
        return id;
    }

public void setId(Integer id) {
        this.id = id;
    }

public String getUsername() {
        return username;
    }

public void setUsername(String username) {
        this.username = username;
    }

public Date getBirthday() {
        return birthday;
    }

public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

public String getGender() {
        return gender;
    }

public void setGender(String gender) {
        this.gender = gender;
    }

public String getAddress() {
        return address;
    }

public void setAddress(String address) {
        this.address = address;
    }

@Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", birthday=" + birthday +
                ", gender='" + gender + '\'' +
                ", address='" + address + '\'' +
                '}';
    }
}
```
- UserMapper.java

```
package com.sunxiaping.mapper;

import com.sunxiaping.domain.User;
import org.apache.ibatis.annotations.*;

import java.util.List;

public interface UserMapper {

/**
     * 查询所有用户信息
     *
     * @return
     */
    @Select(" SELECT * FROM `user`")
    @Results({
            @Result(id = true, property = "id", column = "id"),
            @Result(property = "username", column = "username"),
            @Result(property = "birthday", column = "birthday"),
            @Result(property = "gender", column = "gender"),
            @Result(property = "address", column = "address"),
    })
    List<User> findAll();

/**
     * 添加用户信息
     *
     * @param user
     */
    @Insert(" INSERT INTO `user` (username,birthday,gender,address) VALUES (#{username},#{birthday},#{gender},#{address})")
    void saveUser(User user);

/**
     * 修改用户信息
     *
     * @param user
     */
    @Update(" UPDATE `user` set username = #{username},gender= #{gender} ,address = #{address} WHERE id = #{id} ")
    void updateUser(User user);

/**
     * 删除用户信息
     *
     * @param id
     */
    @Delete(" DELETE FROM `user` WHERE id = #{id} ")
    void deleteById(Integer id);

}
```
- 测试：

```
package com.sunxiaping;

import com.sunxiaping.domain.User;
import com.sunxiaping.mapper.UserMapper;
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 org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.List;

public class UserTest {
    SqlSessionFactory sqlSessionFactory = null;
    SqlSession sqlSession = null;

@Before
    public void before() throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

}

@After
    public void after() {
        if (sqlSession != null) {
            sqlSession.close();
        }
    }

@Test
    public void testFindAll() throws IOException {
        sqlSession = sqlSessionFactory.openSession(true);

UserMapper userMapper = sqlSession.getMapper(UserMapper.class);

List<User> userList = userMapper.findAll();

System.out.println("userList = " + userList);

}

@Test
    public void testSaveUser() {
        sqlSession = sqlSessionFactory.openSession(true);

User user = new User();
        user.setUsername("zhangsan");
        user.setBirthday(new Date());
        user.setGender("男");
        user.setAddress("江苏苏州");

UserMapper userMapper = sqlSession.getMapper(UserMapper.class);

userMapper.saveUser(user);
    }

@Test
    public void testUpdateUser() {
        sqlSession = sqlSessionFactory.openSession(true);

User user = new User();
        user.setId(1);
        user.setUsername("张三");
        user.setGender("女");
        user.setAddress("江苏苏州");
        user.setBirthday(new Date());

UserMapper userMapper = sqlSession.getMapper(UserMapper.class);

userMapper.updateUser(user);

}

@Test
    public void testDeleteById() {
        sqlSession = sqlSessionFactory.openSession(true);

UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        userMapper.deleteById(1);
    }

}
```

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