Mybatis注解开发相关
一、项目构建
1、Java项目目录结构
2、在domain包下创建User实体类
package sun.domain; import java.io.Serializable;
import java.util.Date; /**
* @Classname User
* @Description TODO
* @Date 2020/9/13 14:07
* @Created by Administrator
*/
public class User implements Serializable {
private Integer id;
private String username;
private String address;
private String sex;
private Date birthday; 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 String getAddress() {
return address;
} public void setAddress(String address) {
this.address = address;
} public String getSex() {
return sex;
} public void setSex(String sex) {
this.sex = sex;
} public Date getBirthday() {
return birthday;
} public void setBirthday(Date birthday) {
this.birthday = birthday;
} @Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + '\'' +
", address='" + address + '\'' +
", sex='" + sex + '\'' +
", birthday=" + birthday +
'}';
}
}
User实体类
3、在dao包下创建UserDao接口
package sun.dao; import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import sun.domain.User; import javax.jws.soap.SOAPBinding;
import java.util.List; /**
* @Classname UserDao
* @Description TODO
* @Date 2020/9/13 14:09
* @Created by Administrator
*/
public interface UserDao {
/**
* 查询所有用户
*/
@Select("select * from user")
List<User> findAll(); /**
* 根据id查user
*/
@Select("select * from user where id=#{id}")
User findUserById(Integer id); /**
* 模糊查询
*/
@Select("select * from user where username like #{name}")
List<User> findLike(String name); /**
* 查询记录总数
*/
@Select("select count(1) from user")
int findTotal(); /**
* 添加新用户
*/
@Insert("insert into user(username,birthday,sex,address) values(#{username},#{birthday},#{sex},#{address})")
void saveUser(User user); /**
* 更新用户信息
*/
@Update("update user set username=#{username},address=#{address},birthday=#{birthday},sex=#{sex} where id=#{id}")
void updateUser(User user); /**
* 删除用户
*/
@Delete("delete from user where id=#{id}")
void deleteUser(Integer id);
}
UserDao接口
4、在resource目录下创建SqlMapConfig.xml主配置文件
<?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>
<properties resource="jdbcConfig.properties"></properties> <typeAliases>
<package name="sun.domain"></package>
</typeAliases>
<!--配置环境-->
<environments default="mysql">
<!--配置mysql环境-->
<environment id="mysql">
<!--配置事务类型-->
<transactionManager type="JDBC"></transactionManager>
<!--配置数据库连接池-->
<dataSource type="POOLED">
<!--配置连接数据库基本信息-->
<property name="driver" value="${jdbc.driver}"></property>
<property name="url" value="${jdbc.url}"></property>
<property name="username" value="${jdbc.username}"></property>
<property name="password" value="${jdbc.password}"></property>
</dataSource>
</environment>
</environments> <mappers>
<package name="sun.dao"></package>
</mappers>
</configuration>
SqlMapConfig.xml
5、创建测试类
package sun.test; import org.apache.ibatis.annotations.Select;
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 sun.dao.UserDao;
import sun.domain.User; import java.io.InputStream;
import java.util.List; /**
* @Classname MybatisTest
* @Description TODO
* @Date 2020/9/13 14:57
* @Created by Administrator
*/
public class MybatisTest {
InputStream in;
SqlSessionFactoryBuilder builder;
SqlSessionFactory sessionFactory;
SqlSession sqlSession;
UserDao userDao; @Before
public void init() throws Exception{
in = Resources.getResourceAsStream("SqlMapConfig.xml");
builder = new SqlSessionFactoryBuilder();
sessionFactory = builder.build(in);
sqlSession = sessionFactory.openSession();
userDao = sqlSession.getMapper(UserDao.class);
}
@After
public void destory() throws Exception{
sqlSession.commit();
sqlSession.close();
in.close();
} @Test
public void findAllTest() throws Exception{
List<User> users = userDao.findAll();
for (User user : users) {
System.out.println(user);
}
} @Test
public void findOneTest() throws Exception{
User user = userDao.findUserById(48);
System.out.println(user);
} @Test
public void findLikeTest() throws Exception{
List<User> users = userDao.findLike("%王%");
for (User user : users) {
System.out.println(user);
}
} @Test
public void findTotalTest() throws Exception{
int total = userDao.findTotal();
System.out.println(total);
} @Test
public void saveUserTest() throws Exception{
User user = new User();
user.setUsername("kelvin");
user.setAddress("安徽省宿州市");
userDao.saveUser(user);
} @Test
public void updateTest() throws Exception{
User user = new User();
user.setId(49);
user.setUsername("kelvin");
user.setAddress("安徽省宿州市");
user.setSex("男");
userDao.updateUser(user);
} @Test
public void deleteTest(){
userDao.deleteUser(50);
}
}
测试类
二、构建实体类属性和数据库表字段对应关系
在接口方法中使用@Result来构建实体类属性和数据库表字段之间的关系，后面方法如果想要使用该关系可以使用@ResultMap进行使用。
package sun.dao; import org.apache.ibatis.annotations.*;
import sun.domain.User; import javax.jws.soap.SOAPBinding;
import java.util.List; /**
* @Classname UserDao
* @Description TODO
* @Date 2020/9/13 14:09
* @Created by Administrator
*/
public interface UserDao {
/**
* 查询所有用户
*/
@Select("select * from user")
@Results(id="userMap",value={
@Result(id=true,property = "user_id",column = "id"),
@Result(property = "user_name",column = "username"),
@Result(property = "user_sex",column = "sex"),
@Result(property = "user_address",column = "address"),
@Result(property = "user_birthday",column = "birthday"),
})
List<User> findAll(); /**
* 根据id查user
*/
@Select("select * from user where id=#{id}")
// @ResultMap(value = {"userMap"}) // 正规写法
@ResultMap("userMap") // 只有一个参数 简写
User findUserById(Integer id); /**
* 模糊查询
*/
@Select("select * from user where username like #{name}")
@ResultMap(value = {"userMap"})
List<User> findLike(String name); }
UserDao接口
三、一对一&一对多查询
创建一对一，一对多查询主要使用了@Result中的one属性和many属性。配置one或many中的select和fetchType即可。
Java项目目录结构
1、一对一
1）在domain下创建User和Account实体类
User类：
package sun.domain; import java.io.Serializable;
import java.util.Date;
import java.util.List; /**
* @Classname User
* @Description TODO
* @Date 2020/9/13 14:07
* @Created by Administrator
*/
public class User implements Serializable {
private Integer user_id;
private String user_name;
private String user_address;
private String user_sex;
private Date user_birthday;
private List<Account> accountList; public List<Account> getAccountList() {
return accountList;
} public void setAccountList(List<Account> accountList) {
this.accountList = accountList;
} public Integer getUser_id() {
return user_id;
} public void setUser_id(Integer user_id) {
this.user_id = user_id;
} public String getUser_name() {
return user_name;
} public void setUser_name(String user_name) {
this.user_name = user_name;
} public String getUser_address() {
return user_address;
} public void setUser_address(String user_address) {
this.user_address = user_address;
} public String getUser_sex() {
return user_sex;
} public void setUser_sex(String user_sex) {
this.user_sex = user_sex;
} public Date getUser_birthday() {
return user_birthday;
} public void setUser_birthday(Date user_birthday) {
this.user_birthday = user_birthday;
} @Override
public String toString() {
return "User{" +
"user_id=" + user_id +
", user_name='" + user_name + '\'' +
", user_address='" + user_address + '\'' +
", user_sex='" + user_sex + '\'' +
", user_birthday=" + user_birthday +
'}';
}
}
User
Account类：
package sun.domain; import java.io.Serializable; /**
* @Classname Account
* @Description TODO
* @Date 2020/9/14 8:50
* @Created by Administrator
*/
public class Account implements Serializable {
private Integer id;
private Integer uid;
private Double money;
private User user; public User getUser() {
return user;
} public void setUser(User user) {
this.user = user;
} public Integer getId() {
return id;
} public void setId(Integer id) {
this.id = id;
} public Integer getUid() {
return uid;
} public void setUid(Integer uid) {
this.uid = uid;
} public Double getMoney() {
return money;
} public void setMoney(Double money) {
this.money = money;
} @Override
public String toString() {
return "Account{" +
"id=" + id +
", uid=" + uid +
", money=" + money +
'}';
}
}
Account
2）在dao包下创建UserDao接口和AccountDao接口
UserDao接口：
package sun.dao; import org.apache.ibatis.annotations.*;
import org.apache.ibatis.mapping.FetchType;
import sun.domain.User; import javax.jws.soap.SOAPBinding;
import java.util.List; /**
* @Classname UserDao
* @Description TODO
* @Date 2020/9/13 14:09
* @Created by Administrator
*/
public interface UserDao {
/**
* 查询所有用户
*/
@Select("select * from user")
@Results(id="userMap",value={
@Result(id=true,property = "user_id",column = "id"),
@Result(property = "user_name",column = "username"),
@Result(property = "user_sex",column = "sex"),
@Result(property = "user_address",column = "address"),
@Result(property = "user_birthday",column = "birthday"),
@Result(property = "accountList",column = "id",
many = @Many(select = "sun.dao.AccountDao.findAccountById",
fetchType = FetchType.LAZY))
})
List<User> findAll(); /**
* 根据id查user
*/
@Select("select * from user where id=#{id}")
// @ResultMap(value = {"userMap"}) // 正规写法
@ResultMap("userMap") // 只有一个参数 简写
User findUserById(Integer id); }
UserDao接口
Account接口：
package sun.dao; import org.apache.ibatis.annotations.One;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.mapping.FetchType;
import sun.domain.Account; import java.util.List; /**
* @Classname AccountDao
* @Description TODO
* @Date 2020/9/14 8:52
* @Created by Administrator
*/
public interface AccountDao {
/**
* 查询所有数据
*/
@Select("select * from account")
//配置多对一（一对一）查询
@Results(id = "accountMap",value = {
@Result(id = true,property = "id",column = "id"),
@Result(property = "uid",column = "uid"),
@Result(property = "money",column = "money"),
@Result(property = "user",column = "uid",one = @One(select = "sun.dao.UserDao.findUserById",fetchType= FetchType.EAGER))
})
List<Account> findAll(); /**
* 根据id查user
*/
@Select("select * from account where uid=#{id}")
Account findAccountById(Integer id); }
AccountDao接口
3）创建主配置文件
4）测试
package sun.test; 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 sun.dao.AccountDao;
import sun.domain.Account;
import sun.domain.User; import java.io.InputStream;
import java.util.List; /**
* @Classname MybatisTest
* @Description TODO
* @Date 2020/9/13 14:57
* @Created by Administrator
*/
public class MybatisTest2 {
InputStream in;
SqlSessionFactoryBuilder builder;
SqlSessionFactory sessionFactory;
SqlSession sqlSession;
AccountDao accountDao; @Before
public void init() throws Exception{
in = Resources.getResourceAsStream("SqlMapConfig.xml");
builder = new SqlSessionFactoryBuilder();
sessionFactory = builder.build(in);
sqlSession = sessionFactory.openSession();
accountDao = sqlSession.getMapper(AccountDao.class);
}
@After
public void destory() throws Exception{
sqlSession.commit();
sqlSession.close();
in.close();
}
@Test
public void findAll(){
List<Account> all = accountDao.findAll();
for (Account account : all) {
System.out.println(account);
System.out.println(account.getUser());
}
}
}
2、一对多
1）同上
2）同上
3）同上
4）测试类
package sun.test; 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 sun.dao.UserDao;
import sun.domain.User; import java.io.InputStream;
import java.util.List; /**
* @Classname MybatisTest
* @Description TODO
* @Date 2020/9/13 14:57
* @Created by Administrator
*/
public class MybatisTest {
InputStream in;
SqlSessionFactoryBuilder builder;
SqlSessionFactory sessionFactory;
SqlSession sqlSession;
UserDao userDao; @Before
public void init() throws Exception {
in = Resources.getResourceAsStream("SqlMapConfig.xml");
builder = new SqlSessionFactoryBuilder();
sessionFactory = builder.build(in);
sqlSession = sessionFactory.openSession();
userDao = sqlSession.getMapper(UserDao.class);
} @After
public void destory() throws Exception {
sqlSession.commit();
sqlSession.close();
in.close();
} @Test
public void findAllTest() throws Exception {
List<User> users = userDao.findAll();
for (User user : users) {
System.out.println(user);
System.out.println(user.getAccountList());
}
} }
实体类属性和表字段对应关系、一对一、一对多查询及延迟加载均在@Result注解中配置。
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