视频地址：哔哩哔哩
讲义作业飞书地址：day06作业
基础性作业，加油！
1、SQL语句的编写
-- 1. 查询所有的性别为男(gender 为 1)的 讲师 (job 为 2) , 并根据入职时间, 对员工进行升序排序
select * from emp where gender = 1 and job = 2 order by entry_date asc;-- 2. 根据 入职时间 对公司的员工进行 升序排序 ， 入职时间相同 , 再按照 ID 进行降序排序
select * from emp order by entry_date asc,id desc;-- 3. 查询性别为男(gender 为 1) 且 薪资大于 6000 的员工, 并根据 入职时间 对公司的员工进行 升序排序 ， 入职时间相同 , 再按照 ID 进行降序排序
select * from emp where gender = 1 and salary > 6000 order by entry_date asc ,id desc ;-- 4. 查询性别为男(gender 为 1)的员工 且 在 '2005-10-01' 至 '2018-10-01' 之间入职的员工, 并根据 入职时间 对公司的员工进行 升序排序 ， 入职时间相同 , 再按照 ID 进行降序排序
select * from emp where gender = 1 and (entry_date between '2005-10-01' and '2018-10-01') order by entry_date asc ,id desc;-- 5. 查询姓 '阮' 且 在 '2010-10-01' 之后入职的员工, 并根据入职时间进行升序排序, 并对结果分页操作, 展示第1页员工数据, 每页展示5条记录
select * from emp where name like '阮%' and entry_date > '2010-10-01' order by entry_date asc limit 5;2、通过JDBC程序，基于预编译SQL，执行更新操作
@Testpublic void testUpdate() throws ClassNotFoundException, SQLException {//1.注册驱动Class.forName("com.mysql.cj.jdbc.Driver");//2.获取数据库连接String url = "jdbc:mysql://localhost:3306/web01";String username = "root";String password = "moon";String sql = "update user set password = ?, name = ?, age = ? where id = ?";PreparedStatement ps = DriverManager.getConnection(url, username, password).prepareStatement(sql);ps.setString(1,"haveagoodluck");ps.setString(2,"关羽");ps.setInt(3,32);ps.setInt(4,4);int i = ps.executeUpdate();System.out.println(i);ps.close();}3、通过JDBC程序，基于预编译SQL，执行查询语句
@Testpublic void select() throws ClassNotFoundException, SQLException {//1.注册驱动Class.forName("com.mysql.cj.jdbc.Driver");//2.获取数据库连接String url = "jdbc:mysql://localhost:3306/web01";String username = "root";String password = "moon";String sql = "select id,username,password,name,age from user where age >= ? and id <= ?";PreparedStatement ps = DriverManager.getConnection(url, username, password).prepareStatement(sql);ps.setInt(1,20);ps.setInt(2,4);ResultSet rs = ps.executeQuery();while (rs.next()) {User user = new User(rs.getInt("id"),rs.getString("username"),rs.getString("password"),rs.getString("name"),rs.getInt("age"));System.out.println(user);}rs.close();ps.close();}4、导入项目，基于Mybatis完成SQL语句实现
①导入项目：将文件解压后放在目录里，然后导入xml文件
②创建数据库，创建表
③实现SQL语句（注意更改数据库连接信息，密码更改为自己的，url更改为对应数据库）
- StudentMapper.java
package com.itheima.mapper;import com.itheima.pojo.Student;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;import java.util.List;@Mapper
public interface StudentMapper {@Select("select * from student")public List<Student> findAll();@Insert("insert into student values(null,#{name},#{no},#{gender},#{phone},#{idCard},#{degree},#{graduationDate},#{createTime},#{updateTime})")public void insert(Student s);@Update("update student set no = #{no}, phone = #{phone}, id_card = #{idCard} where id = #{id}")public void update(Student s);//下面两个基于XML配置SQLpublic Student findById(Integer id);public void deleteById(Integer id);}- StudentMapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.itheima.mapper.StudentMapper"><!--resultType：查询返回的单条记录所封装的类型--><select id="findById" resultType="com.itheima.pojo.Student">select * from student where id = #{id}</select><select id="deleteById" resultType="com.itheima.pojo.Student">delete from student where id = #{id}</select></mapper>-
SpringBootMybatisApplicationTests.java
package com.itheima;import com.itheima.mapper.StudentMapper;
import com.itheima.pojo.Student;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;@SpringBootTest
public class SpringBootMybatisApplicationTests {@Autowiredpublic StudentMapper studentMapper;@Testpublic void testFindAll(){studentMapper.findAll().forEach(System.out::println);}@Testpublic void testInsert(){Student s = new Student(null, "小明", "2019011", 1, "13888888888", "123456789012345678", 1, null, null, null);studentMapper.insert(s);}@Testpublic void testUpdate(){Student s = new Student(12, "小明", "2019012", 1, "13888889998", "123456789012345789", 1, null, null, null);studentMapper.update(s);}@Testpublic void testFindById(){System.out.println(studentMapper.findById(5));}@Testpublic void testDeleteById(){studentMapper.deleteById(7);}}
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