1.参数的传递
1)形参的索引，#{0}从0开始
2)形参的索引，#{param1}从1开始
3)对象，通过对象的属性访问
4)Map，通过key来访问
5)注解(@Param("name"))
6)用那个
1)如果方法的参数大于3个要么封装成对象，要么封装成Map
2)如果方法的形参小于3个参数就用注解
创建数据库：
1.创建项目
2.建包建配置文件
com.qf.entity
com.qf.dao
com.qf.mapper
com.qf.utils
mybatis-config.xml
3.con.qf.entity包中创建实体类
package com.qf.entity;
import org.apache.ibatis.type.Alias;
public class User {
private Integer id;
private String name;
private String password;
private String isAdmin;
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getIsAdmin() {
return isAdmin;
}
public void setIsAdmin(String isAdmin) {
this.isAdmin = isAdmin;
}
@Override
public String toString() {
return "User [id=" + id + ", name=" + name + ", password=" + password + ", isAdmin=" + isAdmin + "]";
}
}
4.con.qf.dao包中创建接口
package com.qf.dao;
import java.util.Map;
import org.apache.ibatis.annotations.Param;
import com.qf.entity.User;
public interface IUserDao {
public User getUserById(Integer id);
public void add(User user);
public User login(String name,String password);
public User login2(User user);
public User login3(Map<String,Object> map);
public User login4(@Param("name")String name,@Param("password")String password);
}
5.配置jdbc.properties配置文件
jdbc.url =jdbc:mysql://localhost:3306/1708_mybatis jdbc.name=root jdbc.password=root jdbc.driver=com.mysql.jdbc.Driver
配置mybatis-config.xml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>
<!-- 加载属性文件
resource:本地资源文件
-->
<properties resource="jdbc.properties"></properties>
<typeAliases>
<!-- 给一个对象起别名 -->
<!-- <typeAlias type="com.qf.entity.User" alias="user"/> -->
<!-- 给一个包下面的所有类起别名，默认的别名是类名首字母小写,可以通过@Alias注解修改默认的别名 -->
<package name="com.qf.entity"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC" />
<dataSource type="POOLED">
<property name="driver" value="${jdbc.driver}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.name}" />
<property name="password" value="${jdbc.password}" />
</dataSource>
</environment>
</environments>
</configuration>
6.com.qf.mapper包创建接口的映射文件
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!-- namespace指的就是接口的全类名 -->
<mapper namespace="com.qf.dao.IUserDao">
<resultMap type="com.qf.entity.User" id="userMap2">
<result column="is_admin" property="isAdmin" />
</resultMap>
<resultMap type="com.qf.entity.User" id="userMap" extends="userMap2">
<id column="id" property="id" />
<result column="name" property="name" />
<result column="password" property="password" />
</resultMap>
<!-- id:方法名称 resultType:返回类型 -->
<select id="getUserById" resultMap="userMap">
select * from t_user where
id
= #{id}
</select>
<!-- parameterType:方法的参数类型 -->
<insert id="add" parameterType="user">
insert into t_user
(name,password) values(#{name},#{password})
</insert>
<!--第一种方式通过方法形参的索引，从0开始 -->
<!-- <select id="login" resultMap="userMap"> select * from t_user where
name=#{0} and password=#{1} </select> -->
<!--第二种方式通过方法形参的索引，从param1开始 -->
<select id="login" resultMap="userMap">
select * from t_user where
name=#{param1} and password=#{param2}
</select>
<!-- 第三种方式通过方法是个对象，通过属性名从取值 -->
<select id="login2" resultMap="userMap" parameterType="User">
select *
from t_user where name=#{name} and password=#{password}
</select>
<!-- 第四种方式通过方法是个Map，通过key来取值 -->
<select id="login3" resultMap="userMap" parameterType="User">
select *
from t_user where name=#{name} and password=#{password}
</select>
<!-- 第五种方式方法传递多个参数，用注解中的中的内容来取值 -->
<select id="login4" resultMap="userMap" parameterType="User">
select *
from t_user where name=#{name} and password=#{password}
</select>
</mapper>
7.在mybatis-config.xml里面读取Mapper文件
<!-- Mapper文件 --> <mappers> <mapper resource="com/qf/mapper/IUserDao.xml" /> </mappers>
8.com.qf.util工具类
package com.qf.utils;
import java.io.IOException;
import java.io.InputStream;
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.xml.sax.InputSource;
public class MyBatisUtil {
private static SqlSessionFactory sqlSessionFactory;
public static SqlSessionFactory getSqlSessionFactory() {
if (sqlSessionFactory == null) {
initSqlSessionFactory(); // 为空再去参加
}
return sqlSessionFactory;
}
private static void initSqlSessionFactory() {
InputStream ips = null;
try {
// 1.指定配置文件
ips = Resources.getResourceAsStream("mybatis-config.xml");
// 2.赋值操作
synchronized (MyBatisUtil.class) {
if (sqlSessionFactory == null) {
sqlSessionFactory = new SqlSessionFactoryBuilder().build(ips);
}
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (ips != null) {
try {
ips.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
9.测试类
package com.qf.dao;
import java.util.HashMap;
import java.util.Map;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.log4j.Logger;
import org.junit.Test;
import com.qf.entity.User;
import com.qf.utils.MyBatisUtil;
public class UserDaoTest {
private Logger logger = Logger.getLogger(UserDaoTest.class);
@Test
public void testGetUserById() {
SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession();
IUserDao userDao = sqlSession.getMapper(IUserDao.class);
User user = userDao.getUserById(7);
System.out.println(user);
sqlSession.close();
}
/**
* 测试：1第一种方式通过方法形参的索引，从0开始
*/
@Test
public void testLogin() {
SqlSessionFactory sqlSessionFactory = MyBatisUtil.getSqlSessionFactory();
SqlSession sqlSession = sqlSessionFactory.openSession();
IUserDao userDao = sqlSession.getMapper(IUserDao.class);
User user = userDao.login("张三", "123");
System.out.println(user);
sqlSession.commit();
sqlSession.close();
}
/**
* 第二种方式通过方法形参的索引，从param1开始
*/
@Test
public void testLogin1() {
SqlSessionFactory sqlSessionFactory = MyBatisUtil.getSqlSessionFactory();
SqlSession sqlSession = sqlSessionFactory.openSession();
IUserDao userDao = sqlSession.getMapper(IUserDao.class);
User user = userDao.login("张三", "123");
System.out.println(user);
sqlSession.commit();
sqlSession.close();
}
/**
* 第三种方式通过方法是个对象，通过属性名从取值
*/
@Test
public void testLogin2() {
SqlSessionFactory sqlSessionFactory = MyBatisUtil.getSqlSessionFactory();
SqlSession sqlSession = sqlSessionFactory.openSession();
IUserDao userDao = sqlSession.getMapper(IUserDao.class);
User user =new User();
user.setName("张三");
user.setPassword("123");
user = userDao.login2(user);
System.out.println(user);
sqlSession.commit();
sqlSession.close();
}
/**
* 第四种方式通过方法是个Map，通过key来取值
*/
@Test
public void testLogin3() {
SqlSessionFactory sqlSessionFactory = MyBatisUtil.getSqlSessionFactory();
SqlSession sqlSession = sqlSessionFactory.openSession();
IUserDao userDao = sqlSession.getMapper(IUserDao.class);
Map<String,Object> map=new HashMap<String,Object>();
map.put("name", "张三");
map.put("password", "123");
User user = userDao.login3(map);
System.out.println(user);
sqlSession.commit();
sqlSession.close();
}
/**
* 第五种方式方法传递多个参数，用注解中的中的内容来取值
*/
@Test
public void testLogin4() {
SqlSessionFactory sqlSessionFactory = MyBatisUtil.getSqlSessionFactory();
SqlSession sqlSession = sqlSessionFactory.openSession();
IUserDao userDao = sqlSession.getMapper(IUserDao.class);
User user = userDao.login4("张三", "123");
System.out.println(user);
sqlSession.commit();
sqlSession.close();
}
}