05_动态sql_动态sql与关联映射习题

一. 动态sql

1. if标签

2. where标签

3. foreach标签

二. 动态sql例子

1. 新建一个名为DynamicSql的Java工程, 拷入相关jar包

2. 新建User.java

package com.lywgames.domain;
 
import java.util.Date;
 
public class User {
	private Integer id;
	private String name;
	private String sex;
	private Date birthday;
	private String address;
 
	public User() {
	}
	
	public User(String name, String sex, Date birthday, String address) {
		this.name = name;
		this.sex = sex;
		this.birthday = birthday;
		this.address = address;
	}
	
	public User(Integer id, String name, String sex, Date birthday, String address) {
		this.id = id;
		this.name = name;
		this.sex = sex;
		this.birthday = birthday;
		this.address = address;
	}
 
	public Integer getId() {
		return id;
	}
 
	public void setId(Integer id) {
		this.id = id;
	}
 
	public String getName() {
		return name;
	}
 
	public void setName(String name) {
		this.name = name;
	}
 
	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;
	}
 
	public String getAddress() {
		return address;
	}
 
	public void setAddress(String address) {
		this.address = address;
	}
 
	@Override
	public String toString() {
		return "User [id=" + id + ", name=" + name + ", sex=" + sex + ", birthday=" + birthday + ", address=" + address
				+ "]";
	}
 
}

3. 新建UserMapper.java接口

package com.lywgames.dao;
 
import java.util.List;
import com.lywgames.domain.User;
 
public interface UserMapper {
	public List<User> selectUserByName(String name);
	public List<User> selectUserByIds(List<Integer> ids);
	public List<User> selectUser(User user);
}

4. 在和UserMapper.java接口同一目录下新建UserMapper.xml映射文件

5. 在src目录下新建jdbc.properties数据库属性文件

6. 在src目录下新建SqlMapConfig.xml数据库配置文件

7. 新建Test.java

package com.lywgames;
 
import java.io.InputStream;
import java.util.Arrays;
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;
import com.lywgames.dao.UserMapper;
import com.lywgames.domain.User;
 
public class Test {
	public static void main(String[] args) {
		SqlSession sqlSession = null;
		try {
			// 指定全局配置文件
			String resource = "SqlMapConfig.xml";
			// 读取配置文件
			InputStream inputStream = Resources.getResourceAsStream(resource);
			// 构建sqlSessionFactory
			SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
			// 获取sqlSession
			sqlSession = sqlSessionFactory.openSession();
 
			UserMapper userDao = sqlSession.getMapper(UserMapper.class);
			
			// 查询操作
			List<User> users = userDao.selectUserByName("李");
			for (User user : users) {
				System.out.println(user);
			}
			System.out.println("--------------------------------------");
 
			users = userDao.selectUser(new User(4, "李", "", null, ""));
			for (User user : users) {
				System.out.println(user);
			}
			System.out.println("--------------------------------------");
			
			users = userDao.selectUserByIds(Arrays.asList(4, 5));
			for (User user : users) {
				System.out.println(user);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if(sqlSession != null) {
				// 释放资源
				sqlSession.close();
			}
		}
	}
}

8. 查看user表数据

9. 运行项目