Mybatis-基于注解开发CRUD
目录
环境搭建
mybatis注解建立实体类属性和数据库表中列的对应关系
mybatis注解开发一对一的查询配置
mybatis注解开发一对多的查询配置
mybatis注解开发使用二级缓存
环境搭建
pom文件
jar
org.mybatis
mybatis
3.4.5
mysql
mysql-connector-java
5.1.27
log4j
log4j
1.2.12
junit
junit
4.12
jdbcConfig.properties
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/eesy_mybatis
jdbc.username=root
jdbc.password=1234log4j.properties
# Set root category priority to INFO and its only appender to CONSOLE.
#log4j.rootCategory=INFO, CONSOLE debug info warn error fatal
log4j.rootCategory=debug, CONSOLE, LOGFILE
# Set the enterprise logger category to FATAL and its only appender to CONSOLE.
log4j.logger.org.apache.axis.enterprise=FATAL, CONSOLE
# CONSOLE is set to be a ConsoleAppender using a PatternLayout.
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%d{ISO8601} %-6r [%15.15t] %-5p %30.30c %x - %m\n
# LOGFILE is set to be a File appender using a PatternLayout.
log4j.appender.LOGFILE=org.apache.log4j.FileAppender
log4j.appender.LOGFILE.File=d:\axis.log
log4j.appender.LOGFILE.Append=true
log4j.appender.LOGFILE.layout=org.apache.log4j.PatternLayout
log4j.appender.LOGFILE.layout.ConversionPattern=%d{ISO8601} %-6r [%15.15t] %-5p %30.30c %x - %m\n
SqlMapConfig.xml
实体类
public class User implements Serializable{
private Integer id;
private String username;
private String address;
private String sex;
private Date birthday;
// get/set/tostring方法
}接口
IUserDao
/**
* 在mybatis中针对,CRUD一共有四个注解
* @Select @Insert @Update @Delete
*/
public interface IUserDao {
/**
* 查询所有用户
* @return
*/
@Select("select * from user")
List findAll();
/**
* 保存用户
* @param user
*/
@Insert("insert into user(username,address,sex,birthday)values(#{username},#{address},#{sex},#{birthday})")
void saveUser(User user);
/**
* 更新用户
* @param user
*/
@Update("update user set username=#{username},sex=#{sex},birthday=#{birthday},address=#{address} where id=#{id}")
void updateUser(User user);
/**
* 删除用户
* @param userId
*/
@Delete("delete from user where id=#{id} ")
void deleteUser(Integer userId);
/**
* 根据id查询用户
* @param userId
* @return
*/
@Select("select * from user where id=#{id} ")
User findById(Integer userId);
/**
* 根据用户名称模糊查询
* @param username
* @return
*/
// @Select("select * from user where username like #{username} ")
@Select("select * from user where username like '%${value}%' ")
List findUserByName(String username);
/**
* 查询总用户数量
* @return
*/
@Select("select count(*) from user ")
int findTotalUser();
} 测试类
public class AnnotationCRUDTest {
private InputStream in;
private SqlSessionFactory factory;
private SqlSession session;
private IUserDao userDao;
@Before
public void init()throws Exception{
in = Resources.getResourceAsStream("SqlMapConfig.xml");
factory = new SqlSessionFactoryBuilder().build(in);
session = factory.openSession();
userDao = session.getMapper(IUserDao.class);
}
@After
public void destroy()throws Exception{
session.commit();
session.close();
in.close();
}
@Test
public void testSave(){
User user = new User();
user.setUsername("mybatis annotation");
user.setAddress("北京市昌平区");
userDao.saveUser(user);
}
@Test
public void testUpdate(){
User user = new User();
user.setId(57);
user.setUsername("mybatis annotation update");
user.setAddress("北京市海淀区");
user.setSex("男");
user.setBirthday(new Date());
userDao.updateUser(user);
}
@Test
public void testDelete(){
userDao.deleteUser(51);
}
@Test
public void testFindOne(){
User user = userDao.findById(57);
System.out.println(user);
}
@Test
public void testFindByName(){
// List users = userDao.findUserByName("%mybatis%");
List users = userDao.findUserByName("mybatis");
for(User user : users){
System.out.println(user);
}
}
@Test
public void testFindTotal(){
int total = userDao.findTotalUser();
System.out.println(total);
}
} mybatis注解建立实体类属性和数据库表中列的对应关系
mybatis注解开发一对一的查询配置
public class Account implements Serializable {
private Integer id;
private Integer uid;
private Double money;
//get/set/tostring方法
//多对一（mybatis中称之为一对一）的映射：一个账户只能属于一个用户
private User user;
//get/set方法
}public interface IAccountDao {
/**
* 查询所有账户，并且获取每个账户所属的用户信息
* @return
*/
@Select("select * from account")
@Results(id="accountMap",value = {
@Result(id=true,column = "id",property = "id"),
@Result(column = "uid",property = "uid"),
@Result(column = "money",property = "money"),
@Result(property = "user",column = "uid",one=@One(select="com.itheima.dao.IUserDao.findById",fetchType= FetchType.EAGER))
})
List findAll();
} @Test
public void testFindAll(){
List accounts= accountDao.findAll();
for(Account account: accounts){
System.out.println("---每个用户的信息----");
System.out.println(account);
System.out.println(account.getUser());
}
} mybatis注解开发一对多的查询配置
public class User implements Serializable{
private Integer userId;
private String userName;
private String userAddress;
private String userSex;
private Date userBirthday;
//set/get/tostring方法
//一对多关系映射：一个用户对应多个账户
private List accounts;
//set/get方法
} public interface IAccountDao {
/**
* 根据用户id查询账户信息
* @param userId
* @return
*/
@Select("select * from account where uid = #{userId}")
List findAccountByUid(Integer userId);
} public interface IUserDao {
/**
* 查询所有用户
* @return
*/
@Select("select * from user")
@Results(id="userMap",value={
@Result(id=true,column = "id",property = "userId"),
@Result(column = "username",property = "userName"),
@Result(column = "address",property = "userAddress"),
@Result(column = "sex",property = "userSex"),
@Result(column = "birthday",property = "userBirthday"),
@Result(property = "accounts",column = "id",
many = @Many(select = "com.itheima.dao.IAccountDao.findAccountByUid",
fetchType = FetchType.LAZY))
})
List findAll();
} @Test
public void testFindAll(){
List users= userDao.findAll();
for(User user: users){
System.out.println("---每个用户的信息----");
System.out.println(user);
System.out.println(user.getAccounts());
}
} mybatis注解开发使用二级缓存
