[上海|荣耀师兄]JAVA-蒋新益|2017年10月02日的日报-技能树.IT修真院

发表于： 2017-10-02 22:10:04

2 934

今天完成的事

完成Task2的雏形代码

import java.util.Arrays;
public class Student {
    private long studentId;// 学生ID
    private String name ;// 姓名
    public long getStudentId() {
        return studentId;
    }
    public void setStudentId(long studentId) {
        this.studentId = studentId;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    @Override
    public String toString() {
        return "Student{" +
                "studentId=" + studentId +
                ", name='" + name + '\'' +
                '}';
    }
}

这是实体类，目前只有两个属性，我觉得属性少一些可以方便我理解，理解以后后续添加别的属性也可以更顺畅

import me.jnshu.entity.Student;
import org.apache.ibatis.annotations.Param;
import java.util.List;
public interface StudentDao {
    /**
     * 通过ID查询学生
     *
     * @param studentId
     * @return
     */
    Student queryById(long studentId);
    /**
     * 查询所有学生
     *
     * @param offset 查询起始位置
     * @param limit 查询条数
     * @return
     */
    List<Student> queryAll(@Param("offset") int offset, @Param("limit") int limit);
}

这是接口

<?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";>;
<mapper namespace="me.jnshu.Dao.StudentDao">
    <select id="queryById" resultType="Student" parameterType="long">
        <!-- 具体的sql -->
        SELECT
        studentId,
        name
        FROM
        student
        WHERE
        studentId = #{studentId}
    </select>
    <select id="queryAll" resultType="Student">
        SELECT
        studentId,
        name
        FROM
        student
        ORDER BY
        studentId
        LIMIT #{offset}, #{limit}
    </select>
</mapper>