基于阿里数据库连接池Druid和Apache封装工具类DBUtil的JDBC实现对数据库视图的查询和表的增删改查操作
1. Druid
-
Druid首先是一个数据库连接池。Druid是目前最好的数据库连接池，在功能、性能、扩展性方面，都超过其他数据库连接池，包括DBCP、C3P0、BoneCP、Proxool、JBoss DataSource。Druid已经在阿里巴巴部署了超过600个应用，经过一年多生产环境大规模部署的严苛考验。Druid是阿里巴巴开发的号称为监控而生的数据库连接池！
-
它有三个特点：
- 处理的数据量规模较大。
- 可以进行数据的实时查询展示。
- 它的查询模式是交互式的，这也说明其查询并发能力有限。
-
Druid 之所以能够在 OLAP 家族中占据一席之地，主要依赖其强大的 MPP 架构设计，关于它的架构，这里就不展开描述了，感兴趣的同学可以登陆 官网 进行了解。
2. Apache工具类DBUtil
- 点此下载
- Apache Commons DbUtils工具包使用介绍
具体介绍上面很详细，也可以看我的代码。
3.代码结构
本人的项目并不是在项目的根目录下面建立的，所以里面有些路径是需要修改的。可以把代码看做参考：
分别代码：
- Test
package com.student.control;
import com.student.dao.sqlstatements.SqlStatement;
import com.student.dao.studao.CRUD_StudentDao;
import com.student.util.DruidConnectionPool;
import java.sql.Connection;
import java.util.List;
public class Test {
// DruidConnectionPool druidConnectionPool = new DruidConnectionPool();
public static void main(String[] args) {
Connection connection = DruidConnectionPool.getConnection();
CRUD_StudentDao crud_studentDao = new CRUD_StudentDao();
List list ;
int rows = 0;
rows = crud_studentDao.updateTable(SqlStatement.Insert_Check,2017010105,01,"2020-02-18 11:01:54");
System.out.println("影响了 "+rows+" 行.");
// 2 查询某个班的 某天的所有考勤信息（查）
// list = crud_studentDao.selectV_class_check(SqlStatement.Select_Class_Day_All_Check,"计科一班","%2020-02-13%");
// 3 查某个学生 2 月的所有考勤情况（查）
// list = crud_studentDao.selectV_student_check(SqlStatement.Select_Student_Month_All_Check,"张三","%2020-02%");
// System.out.println(list);
}
}
- SqlStatement
package com.student.dao.sqlstatements;
// 1 给某个学生记录 某天的考勤信息（增）
//
// 2 查询某个班的 某天的所有考勤信息（查）
//
// 3 查某个学生 2 月的所有考勤情况（查）
//
public interface SqlStatement {
// 1 给某个学生记录 某天的考勤信息（增）
String Insert_Check = "INSERT INTO checks (s_id,c_id,check_time) VALUES (?,?,?)";
//SELECT * FROM v_class_check WHERE c_name ='计科一班' AND check_time LIKE '%2020-02-17%';
// 2 查询某个班的 某天的所有考勤信息（查）
String Select_Class_Day_All_Check = "select * from v_class_check where c_name = ? AND check_time LIKE ?";
// 3 查某个学生 2 月的所有考勤情况（查）
String Select_Student_Month_All_Check = "SELECT * FROM select_stu_2month WHERE s_name = ? AND check_time LIKE ?";
}
- CRUD_StudentDao
package com.student.dao.studao;
import com.student.util.DruidConnectionPool;
import com.student.vo.V_class_check;
import com.student.vo.V_student_check;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;
public class CRUD_StudentDao {
Connection connection = DruidConnectionPool.getConnection();
int rows = 0;
List list ;
/**
* 根据sql语句，进行对应的表中的字段的更新
* @param sql
* 预处理好的PreperedStatement
* @param args
* 传递的参数值，不过是以数组的另一种写法
* @return
*/
public int updateTable(String sql,Object ...args){
try {
QueryRunner queryRunner = new QueryRunner();
rows = queryRunner.update(connection,sql,args);
System.out.println("affacts "+rows+" rows.");
connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
return rows;
}
/**
* 查询某个班的 某天的所有考勤信息（查）
* 根据sql语句进行表查询，并返回结果集
* @param sql
* @param args
* @return
*/
public List selectV_class_check(String sql,String ...args){
try {
QueryRunner queryRunner = new QueryRunner();
list = queryRunner.query(connection,sql,new BeanListHandler<V_class_check>(V_class_check.class),args);
connection.close();
}catch (Exception e){
e.printStackTrace();
}
return list;
}
/**
* 查某个学生 2 月的所有考勤情况（查）
* @param sql
* @param args
* @return
*/
public List selectV_student_check (String sql,String ...args){
try {
QueryRunner queryRunner = new QueryRunner();
list = queryRunner.query(connection,sql,new BeanListHandler<V_student_check>(V_student_check.class),args);
connection.close();
}catch (Exception e){
e.printStackTrace();
}
return list;
}
}
- DruidConnectionPool
package com.student.util;
import com.alibaba.druid.pool.DruidDataSourceFactory;
import javax.sql.DataSource;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.sql.Connection;
import java.util.Properties;
public class DruidConnectionPool {
static Connection connection;
public static Connection getConnection() {
try {
FileInputStream fileInputStream = new FileInputStream("./src/com/student/druid.properties");
Properties properties = new Properties();
properties.load(fileInputStream);
DataSource dataSource = DruidDataSourceFactory.createDataSource(properties);
connection= dataSource.getConnection();
System.out.println(connection);
} catch (Exception e) {
e.printStackTrace();
}
return connection;
}
}
- V_class_check
package com.student.vo;
import java.sql.Timestamp;
public class V_class_check {
private int c_id,s_id;
private String c_name,s_name;
private Timestamp check_time;
public V_class_check() {
}
public V_class_check(int c_id, int s_id, String c_name, String s_name, Timestamp check_time) {
this.c_id = c_id;
this.s_id = s_id;
this.c_name = c_name;
this.s_name = s_name;
this.check_time = check_time;
}
public int getC_id() {
return c_id;
}
public void setC_id(int c_id) {
this.c_id = c_id;
}
public int getS_id() {
return s_id;
}
public void setS_id(int s_id) {
this.s_id = s_id;
}
public String getC_name() {
return c_name;
}
public void setC_name(String c_name) {
this.c_name = c_name;
}
public String getS_name() {
return s_name;
}
public void setS_name(String s_name) {
this.s_name = s_name;
}
public Timestamp getCheck_time() {
return check_time;
}
public void setCheck_time(Timestamp check_time) {
this.check_time = check_time;
}
@Override
public String toString() {
return "V_class_check{" +
"c_id=" + c_id +
", s_id=" + s_id +
", c_name='" + c_name + '\'' +
", s_name='" + s_name + '\'' +
", check_time=" + check_time +
'}';
}
}
- V_student_check
package com.student.vo;
import java.sql.Timestamp;
public class V_student_check {
private int s_id;
private String s_name,c_name;
private Timestamp check_time;
public V_student_check() {
}
public V_student_check(int s_id, String s_name, String c_name, Timestamp check_time) {
this.s_id = s_id;
this.s_name = s_name;
this.c_name = c_name;
this.check_time = check_time;
}
public int getS_id() {
return s_id;
}
public void setS_id(int s_id) {
this.s_id = s_id;
}
public String getS_name() {
return s_name;
}
public void setS_name(String s_name) {
this.s_name = s_name;
}
public String getC_name() {
return c_name;
}
public void setC_name(String c_name) {
this.c_name = c_name;
}
public Timestamp getCheck_time() {
return check_time;
}
public void setCheck_time(Timestamp check_time) {
this.check_time = check_time;
}
@Override
public String toString() {
return "V_student_check{" +
"s_id=" + s_id +
", s_name='" + s_name + '\'' +
", c_name='" + c_name + '\'' +
", check_time=" + check_time +
'}';
}
}
- druid.properties
driverClassName=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/student_check?characterEncoding=utf8&useSSL=false
username=root
password=Admin888.
#初始连接数
initialSize=5
#最大连接数
maxActive=10
#最大等待时间
maxWait=3000
#最大空闲数
# maxIdle=8
#最小空闲数
# minIdle=3
#下面的代码用来解决一个报错的，说是Spingboot配置什么的，但是目前并没有进行那么复杂的操作。所以等以后再来看具体的原因
# com.alibaba.druid.pool.DruidDataSource error
# 严重: testWhileIdle is true, validationQuery not set
timeBetweenEvictionRunsMillis=60000
minEvictableIdleTimeMillis=300000
validationQuery=SELECT 1
testWhileIdle=true
testOnBorrow=false
testOnReturn=false
poolPreparedStatements=false
maxPoolPreparedStatementPerConnectionSize=200
# validationQuery = "SELECT 1" 验证连接是否可用，使用的SQL语句
# testWhileIdle = "true" 指明连接是否被空闲连接回收器(如果有)进行检验.如果检测失败,则连接将被从池中去除.
# testOnBorrow = "false" 借出连接时不要测试，否则很影响性能
# timeBetweenEvictionRunsMillis = "30000" 每30秒运行一次空闲连接回收器
# minEvictableIdleTimeMillis = "1800000" 池中的连接空闲30分钟后被回收,默认值就是30分钟。
# numTestsPerEvictionRun="3" 在每次空闲连接回收器线程(如果有)运行时检查的连接数量，默认值就是3.
4. SQL脚本和数据库结构
/*
Navicat Premium Data Transfer
Source Server : 本地连接
Source Server Type : MySQL
Source Server Version : 80019
Source Host : localhost:3306
Source Schema : student_check
Target Server Type : MySQL
Target Server Version : 80019
File Encoding : 65001
Date: 18/02/2020 19:34:33
*/
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for checks
-- ----------------------------
DROP TABLE IF EXISTS `checks`;
CREATE TABLE `checks` (
`chno` int NOT NULL AUTO_INCREMENT,
`s_id` int NOT NULL,
`c_id` int NOT NULL,
`check_time` datetime DEFAULT NULL,
PRIMARY KEY (`chno`,`s_id`,`c_id`),
UNIQUE KEY `uq_chno` (`chno`) USING BTREE,
KEY `fk_checks_students_1` (`s_id`),
KEY `fk_checks_classes_1` (`c_id`),
CONSTRAINT `fk_checks_classes_1` FOREIGN KEY (`c_id`) REFERENCES `classes` (`c_id`),
CONSTRAINT `fk_checks_students_1` FOREIGN KEY (`s_id`) REFERENCES `students` (`s_id`)
) ENGINE=InnoDB AUTO_INCREMENT=21 DEFAULT CHARSET=utf8 COLLATE=utf8_bin;
-- ----------------------------
-- Records of checks
-- ----------------------------
BEGIN;
INSERT INTO `checks` VALUES (1, 2017010101, 1, '2020-02-10 11:01:54');
INSERT INTO `checks` VALUES (2, 2017010101, 1, '2020-02-11 11:02:18');
INSERT INTO `checks` VALUES (3, 2017010101, 1, '2020-02-12 11:02:34');
INSERT INTO `checks` VALUES (4, 2017010101, 1, '2020-02-13 11:02:52');
INSERT INTO `checks` VALUES (5, 2017010102, 1, '2020-02-10 11:03:14');
INSERT INTO `checks` VALUES (6, 2017010102, 1, '2020-02-11 11:03:27');
INSERT INTO `checks` VALUES (7, 2017010102, 1, '2020-02-12 11:03:39');
INSERT INTO `checks` VALUES (8, 2017010102, 1, '2020-02-13 11:03:51');
INSERT INTO `checks` VALUES (9, 2017010103, 1, '2020-02-10 11:04:02');
INSERT INTO `checks` VALUES (10, 2017010103, 1, '2020-02-11 11:04:15');
INSERT INTO `checks` VALUES (11, 2017010103, 1, '2020-02-12 11:04:26');
INSERT INTO `checks` VALUES (12, 2017010103, 1, '2020-02-13 11:04:45');
INSERT INTO `checks` VALUES (13, 2017010104, 1, '2020-02-10 11:04:56');
INSERT INTO `checks` VALUES (14, 2017010104, 1, '2020-02-11 11:05:05');
INSERT INTO `checks` VALUES (15, 2017010104, 1, '2020-02-12 11:05:15');
INSERT INTO `checks` VALUES (16, 2017010104, 1, '2020-02-13 11:05:24');
INSERT INTO `checks` VALUES (17, 2017010101, 1, '2020-02-17 11:45:53');
INSERT INTO `checks` VALUES (18, 2017010101, 1, '2020-01-22 11:01:54');
INSERT INTO `checks` VALUES (19, 2017010101, 1, '2020-02-18 11:01:54');
COMMIT;
-- ----------------------------
-- Table structure for classes
-- ----------------------------
DROP TABLE IF EXISTS `classes`;
CREATE TABLE `classes` (
`c_id` int NOT NULL AUTO_INCREMENT,
`t_id` int DEFAULT NULL,
`c_name` varchar(25) COLLATE utf8_bin DEFAULT NULL,
PRIMARY KEY (`c_id`),
KEY `fk_classes_teachers_1` (`t_id`),
CONSTRAINT `fk_classes_teachers_1` FOREIGN KEY (`t_id`) REFERENCES `teachers` (`t_id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 COLLATE=utf8_bin;
-- ----------------------------
-- Records of classes
-- ----------------------------
BEGIN;
INSERT INTO `classes` VALUES (1, 1, '计科一班');
INSERT INTO `classes` VALUES (2, 2, '医信班');
INSERT INTO `classes` VALUES (3, 3, '信管班');
INSERT INTO `classes` VALUES (4, 4, '计科二班');
COMMIT;
-- ----------------------------
-- Table structure for sdept
-- ----------------------------
DROP TABLE IF EXISTS `sdept`;
CREATE TABLE `sdept` (
`sdept_id` int NOT NULL AUTO_INCREMENT,
`sdept_name` varchar(30) COLLATE utf8_bin DEFAULT NULL,
`sdept_loc` varchar(100) COLLATE utf8_bin DEFAULT NULL,
`sdept_tel` varchar(11) COLLATE utf8_bin DEFAULT NULL,
PRIMARY KEY (`sdept_id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8 COLLATE=utf8_bin;
-- ----------------------------
-- Records of sdept
-- ----------------------------
BEGIN;
INSERT INTO `sdept` VALUES (1, '信息科学与工程学院', '三教三楼', '88485568');
INSERT INTO `sdept` VALUES (2, '人文与管理学院', '三教五楼', '88485567');
COMMIT;
-- ----------------------------
-- Table structure for sdept_class
-- ----------------------------
DROP TABLE IF EXISTS `sdept_class`;
CREATE TABLE `sdept_class` (
`sdc_id` int NOT NULL AUTO_INCREMENT,
`sdept_id` int DEFAULT NULL,
`c_id` int DEFAULT NULL,
PRIMARY KEY (`sdc_id`),
KEY `fk_sdept_class_sdept_1` (`sdept_id`),
KEY `fk_sdept_class_classes_1` (`c_id`),
CONSTRAINT `fk_sdept_class_classes_1` FOREIGN KEY (`c_id`) REFERENCES `classes` (`c_id`),
CONSTRAINT `fk_sdept_class_sdept_1` FOREIGN KEY (`sdept_id`) REFERENCES `sdept` (`sdept_id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 COLLATE=utf8_bin;
-- ----------------------------
-- Records of sdept_class
-- ----------------------------
BEGIN;
INSERT INTO `sdept_class` VALUES (1, 1, 1);
INSERT INTO `sdept_class` VALUES (2, 1, 2);
INSERT INTO `sdept_class` VALUES (3, 1, 3);
INSERT INTO `sdept_class` VALUES (4, 1, 4);
COMMIT;
-- ----------------------------
-- Table structure for select_stu_2month
-- ----------------------------
DROP TABLE IF EXISTS `select_stu_2month`;
CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `select_stu_2month` AS select `students`.`s_id` AS `s_id`,`students`.`s_name` AS `s_name`,`c`.`c_name` AS `c_name`,`checks`.`check_time` AS `check_time` from (((`students` join `stu_class` `sc` on((`students`.`s_id` = `sc`.`s_id`))) join `classes` `c` on((`sc`.`c_id` = `c`.`c_id`))) join `checks` on(((`checks`.`s_id` = `students`.`s_id`) and (`checks`.`c_id` = `c`.`c_id`))));
-- ----------------------------
-- Records of select_stu_2month
-- ----------------------------
BEGIN;
INSERT INTO `select_stu_2month` VALUES (2017010101, '张三', '计科一班', '2020-02-10 11:01:54');
INSERT INTO `select_stu_2month` VALUES (2017010101, '张三', '计科一班', '2020-02-11 11:02:18');
INSERT INTO `select_stu_2month` VALUES (2017010101, '张三', '计科一班', '2020-02-12 11:02:34');
INSERT INTO `select_stu_2month` VALUES (2017010101, '张三', '计科一班', '2020-02-13 11:02:52');
INSERT INTO `select_stu_2month` VALUES (2017010101, '张三', '计科一班', '2020-02-17 11:45:53');
INSERT INTO `select_stu_2month` VALUES (2017010101, '张三', '计科一班', '2020-01-22 11:01:54');
INSERT INTO `select_stu_2month` VALUES (2017010101, '张三', '计科一班', '2020-02-18 11:01:54');
INSERT INTO `select_stu_2month` VALUES (2017010102, '李四', '计科一班', '2020-02-10 11:03:14');
INSERT INTO `select_stu_2month` VALUES (2017010102, '李四', '计科一班', '2020-02-11 11:03:27');
INSERT INTO `select_stu_2month` VALUES (2017010102, '李四', '计科一班', '2020-02-12 11:03:39');
INSERT INTO `select_stu_2month` VALUES (2017010102, '李四', '计科一班', '2020-02-13 11:03:51');
INSERT INTO `select_stu_2month` VALUES (2017010103, '王五', '计科一班', '2020-02-10 11:04:02');
INSERT INTO `select_stu_2month` VALUES (2017010103, '王五', '计科一班', '2020-02-11 11:04:15');
INSERT INTO `select_stu_2month` VALUES (2017010103, '王五', '计科一班', '2020-02-12 11:04:26');
INSERT INTO `select_stu_2month` VALUES (2017010103, '王五', '计科一班', '2020-02-13 11:04:45');
INSERT INTO `select_stu_2month` VALUES (2017010104, '赵柳', '计科一班', '2020-02-10 11:04:56');
INSERT INTO `select_stu_2month` VALUES (2017010104, '赵柳', '计科一班', '2020-02-11 11:05:05');
INSERT INTO `select_stu_2month` VALUES (2017010104, '赵柳', '计科一班', '2020-02-12 11:05:15');
INSERT INTO `select_stu_2month` VALUES (2017010104, '赵柳', '计科一班', '2020-02-13 11:05:24');
COMMIT;
-- ----------------------------
-- Table structure for stu_class
-- ----------------------------
DROP TABLE IF EXISTS `stu_class`;
CREATE TABLE `stu_class` (
`sc_id` int NOT NULL AUTO_INCREMENT,
`s_id` int DEFAULT NULL,
`c_id` int DEFAULT NULL,
PRIMARY KEY (`sc_id`),
KEY `fk_stu_class_students_1` (`s_id`),
KEY `fk_stu_class_classes_1` (`c_id`),
CONSTRAINT `fk_stu_class_classes_1` FOREIGN KEY (`c_id`) REFERENCES `classes` (`c_id`),
CONSTRAINT `fk_stu_class_students_1` FOREIGN KEY (`s_id`) REFERENCES `students` (`s_id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 COLLATE=utf8_bin;
-- ----------------------------
-- Records of stu_class
-- ----------------------------
BEGIN;
INSERT INTO `stu_class` VALUES (1, 2017010101, 1);
INSERT INTO `stu_class` VALUES (2, 2017010102, 1);
INSERT INTO `stu_class` VALUES (3, 2017010103, 1);
INSERT INTO `stu_class` VALUES (4, 2017010104, 1);
COMMIT;
-- ----------------------------
-- Table structure for stu_class_sdept
-- ----------------------------
DROP TABLE IF EXISTS `stu_class_sdept`;
CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `stu_class_sdept` AS select `students`.`s_id` AS `学号`,`students`.`s_name` AS `姓名`,`c`.`c_name` AS `班级`,`sdept`.`sdept_name` AS `院系` from ((((`students` join `stu_class` `sc` on((`students`.`s_id` = `sc`.`s_id`))) join `classes` `c` on((`c`.`c_id` = `sc`.`c_id`))) join `sdept_class` on((`sdept_class`.`c_id` = `c`.`c_id`))) join `sdept` on((`sdept`.`sdept_id` = `sdept_class`.`sdept_id`)));
-- ----------------------------
-- Records of stu_class_sdept
-- ----------------------------
BEGIN;
INSERT INTO `stu_class_sdept` VALUES (2017010101, '张三', '计科一班', '信息科学与工程学院');
INSERT INTO `stu_class_sdept` VALUES (2017010102, '李四', '计科一班', '信息科学与工程学院');
INSERT INTO `stu_class_sdept` VALUES (2017010103, '王五', '计科一班', '信息科学与工程学院');
INSERT INTO `stu_class_sdept` VALUES (2017010104, '赵柳', '计科一班', '信息科学与工程学院');
COMMIT;
-- ----------------------------
-- Table structure for stu_class_sdept_check
-- ----------------------------
DROP TABLE IF EXISTS `stu_class_sdept_check`;
CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `stu_class_sdept_check` AS select `students`.`s_id` AS `学号`,`students`.`s_name` AS `姓名`,`c`.`c_name` AS `班级`,`sdept`.`sdept_name` AS `院系`,`checks`.`check_time` AS `打卡时间` from (((((`students` join `stu_class` `sc` on((`students`.`s_id` = `sc`.`s_id`))) join `classes` `c` on((`c`.`c_id` = `sc`.`c_id`))) join `sdept_class` on((`sdept_class`.`c_id` = `c`.`c_id`))) join `sdept` on((`sdept`.`sdept_id` = `sdept_class`.`sdept_id`))) join `checks` on(((`students`.`s_id` = `checks`.`s_id`) and (`c`.`c_id` = `checks`.`c_id`))));
-- ----------------------------
-- Records of stu_class_sdept_check
-- ----------------------------
BEGIN;
INSERT INTO `stu_class_sdept_check` VALUES (2017010101, '张三', '计科一班', '信息科学与工程学院', '2020-02-10 11:01:54');
INSERT INTO `stu_class_sdept_check` VALUES (2017010101, '张三', '计科一班', '信息科学与工程学院', '2020-02-11 11:02:18');
INSERT INTO `stu_class_sdept_check` VALUES (2017010101, '张三', '计科一班', '信息科学与工程学院', '2020-02-12 11:02:34');
INSERT INTO `stu_class_sdept_check` VALUES (2017010101, '张三', '计科一班', '信息科学与工程学院', '2020-02-13 11:02:52');
INSERT INTO `stu_class_sdept_check` VALUES (2017010101, '张三', '计科一班', '信息科学与工程学院', '2020-02-17 11:45:53');
INSERT INTO `stu_class_sdept_check` VALUES (2017010101, '张三', '计科一班', '信息科学与工程学院', '2020-01-22 11:01:54');
INSERT INTO `stu_class_sdept_check` VALUES (2017010101, '张三', '计科一班', '信息科学与工程学院', '2020-02-18 11:01:54');
INSERT INTO `stu_class_sdept_check` VALUES (2017010102, '李四', '计科一班', '信息科学与工程学院', '2020-02-10 11:03:14');
INSERT INTO `stu_class_sdept_check` VALUES (2017010102, '李四', '计科一班', '信息科学与工程学院', '2020-02-11 11:03:27');
INSERT INTO `stu_class_sdept_check` VALUES (2017010102, '李四', '计科一班', '信息科学与工程学院', '2020-02-12 11:03:39');
INSERT INTO `stu_class_sdept_check` VALUES (2017010102, '李四', '计科一班', '信息科学与工程学院', '2020-02-13 11:03:51');
INSERT INTO `stu_class_sdept_check` VALUES (2017010103, '王五', '计科一班', '信息科学与工程学院', '2020-02-10 11:04:02');
INSERT INTO `stu_class_sdept_check` VALUES (2017010103, '王五', '计科一班', '信息科学与工程学院', '2020-02-11 11:04:15');
INSERT INTO `stu_class_sdept_check` VALUES (2017010103, '王五', '计科一班', '信息科学与工程学院', '2020-02-12 11:04:26');
INSERT INTO `stu_class_sdept_check` VALUES (2017010103, '王五', '计科一班', '信息科学与工程学院', '2020-02-13 11:04:45');
INSERT INTO `stu_class_sdept_check` VALUES (2017010104, '赵柳', '计科一班', '信息科学与工程学院', '2020-02-10 11:04:56');
INSERT INTO `stu_class_sdept_check` VALUES (2017010104, '赵柳', '计科一班', '信息科学与工程学院', '2020-02-11 11:05:05');
INSERT INTO `stu_class_sdept_check` VALUES (2017010104, '赵柳', '计科一班', '信息科学与工程学院', '2020-02-12 11:05:15');
INSERT INTO `stu_class_sdept_check` VALUES (2017010104, '赵柳', '计科一班', '信息科学与工程学院', '2020-02-13 11:05:24');
COMMIT;
-- ----------------------------
-- Table structure for students
-- ----------------------------
DROP TABLE IF EXISTS `students`;
CREATE TABLE `students` (
`s_id` int NOT NULL AUTO_INCREMENT,
`s_name` varchar(20) COLLATE utf8_bin DEFAULT NULL,
`s_sex` varchar(5) COLLATE utf8_bin DEFAULT NULL,
`s_grade` int DEFAULT NULL,
`s_loc` varchar(255) COLLATE utf8_bin DEFAULT NULL,
PRIMARY KEY (`s_id`)
) ENGINE=InnoDB AUTO_INCREMENT=2017010105 DEFAULT CHARSET=utf8 COLLATE=utf8_bin;
-- ----------------------------
-- Records of students
-- ----------------------------
BEGIN;
INSERT INTO `students` VALUES (2017010101, '张三', '男', 2017, '湖南长沙');
INSERT INTO `students` VALUES (2017010102, '李四', '男', 2017, '湖南常德');
INSERT INTO `students` VALUES (2017010103, '王五', '女', 2017, '湖南岳阳');
INSERT INTO `students` VALUES (2017010104, '赵柳', '女', 2017, '湖南衡阳');
COMMIT;
-- ----------------------------
-- Table structure for teachers
-- ----------------------------
DROP TABLE IF EXISTS `teachers`;
CREATE TABLE `teachers` (
`t_id` int NOT NULL AUTO_INCREMENT,
`t_name` varchar(10) COLLATE utf8_bin DEFAULT NULL,
`t_tel` varchar(11) COLLATE utf8_bin DEFAULT NULL,
PRIMARY KEY (`t_id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 COLLATE=utf8_bin;
-- ----------------------------
-- Records of teachers
-- ----------------------------
BEGIN;
INSERT INTO `teachers` VALUES (1, '王老师', '13107342356');
INSERT INTO `teachers` VALUES (2, '刘老师', '13107314569');
INSERT INTO `teachers` VALUES (3, '罗老师', '12456892356');
INSERT INTO `teachers` VALUES (4, '陈老师', '12545784521');
COMMIT;
-- ----------------------------
-- Table structure for v_class_check
-- ----------------------------
DROP TABLE IF EXISTS `v_class_check`;
CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v_class_check` AS select `c`.`c_id` AS `c_id`,`c`.`c_name` AS `c_name`,`students`.`s_id` AS `s_id`,`students`.`s_name` AS `s_name`,`checks`.`check_time` AS `check_time` from (((`classes` `c` join `stu_class` `sc` on((`sc`.`c_id` = `c`.`c_id`))) join `students` on((`students`.`s_id` = `sc`.`s_id`))) join `checks` on(((`checks`.`c_id` = `c`.`c_id`) and (`checks`.`s_id` = `students`.`s_id`))));
-- ----------------------------
-- Records of v_class_check
-- ----------------------------
BEGIN;
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010101, '张三', '2020-02-10 11:01:54');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010101, '张三', '2020-02-11 11:02:18');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010101, '张三', '2020-02-12 11:02:34');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010101, '张三', '2020-02-13 11:02:52');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010101, '张三', '2020-02-17 11:45:53');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010101, '张三', '2020-01-22 11:01:54');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010101, '张三', '2020-02-18 11:01:54');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010102, '李四', '2020-02-10 11:03:14');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010102, '李四', '2020-02-11 11:03:27');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010102, '李四', '2020-02-12 11:03:39');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010102, '李四', '2020-02-13 11:03:51');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010103, '王五', '2020-02-10 11:04:02');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010103, '王五', '2020-02-11 11:04:15');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010103, '王五', '2020-02-12 11:04:26');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010103, '王五', '2020-02-13 11:04:45');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010104, '赵柳', '2020-02-10 11:04:56');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010104, '赵柳', '2020-02-11 11:05:05');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010104, '赵柳', '2020-02-12 11:05:15');
INSERT INTO `v_class_check` VALUES (1, '计科一班', 2017010104, '赵柳', '2020-02-13 11:05:24');
COMMIT;
-- ----------------------------
-- View structure for select_stu_2month
-- ----------------------------
DROP VIEW IF EXISTS `select_stu_2month`;
CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `select_stu_2month` AS select `students`.`s_id` AS `s_id`,`students`.`s_name` AS `s_name`,`c`.`c_name` AS `c_name`,`checks`.`check_time` AS `check_time` from (((`students` join `stu_class` `sc` on((`students`.`s_id` = `sc`.`s_id`))) join `classes` `c` on((`sc`.`c_id` = `c`.`c_id`))) join `checks` on(((`checks`.`s_id` = `students`.`s_id`) and (`checks`.`c_id` = `c`.`c_id`))));
-- ----------------------------
-- View structure for stu_class_sdept
-- ----------------------------
DROP VIEW IF EXISTS `stu_class_sdept`;
CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `stu_class_sdept` AS select `students`.`s_id` AS `学号`,`students`.`s_name` AS `姓名`,`c`.`c_name` AS `班级`,`sdept`.`sdept_name` AS `院系` from ((((`students` join `stu_class` `sc` on((`students`.`s_id` = `sc`.`s_id`))) join `classes` `c` on((`c`.`c_id` = `sc`.`c_id`))) join `sdept_class` on((`sdept_class`.`c_id` = `c`.`c_id`))) join `sdept` on((`sdept`.`sdept_id` = `sdept_class`.`sdept_id`)));
-- ----------------------------
-- View structure for stu_class_sdept_check
-- ----------------------------
DROP VIEW IF EXISTS `stu_class_sdept_check`;
CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `stu_class_sdept_check` AS select `students`.`s_id` AS `学号`,`students`.`s_name` AS `姓名`,`c`.`c_name` AS `班级`,`sdept`.`sdept_name` AS `院系`,`checks`.`check_time` AS `打卡时间` from (((((`students` join `stu_class` `sc` on((`students`.`s_id` = `sc`.`s_id`))) join `classes` `c` on((`c`.`c_id` = `sc`.`c_id`))) join `sdept_class` on((`sdept_class`.`c_id` = `c`.`c_id`))) join `sdept` on((`sdept`.`sdept_id` = `sdept_class`.`sdept_id`))) join `checks` on(((`students`.`s_id` = `checks`.`s_id`) and (`c`.`c_id` = `checks`.`c_id`))));
-- ----------------------------
-- View structure for v_class_check
-- ----------------------------
DROP VIEW IF EXISTS `v_class_check`;
CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v_class_check` AS select `c`.`c_id` AS `c_id`,`c`.`c_name` AS `c_name`,`students`.`s_id` AS `s_id`,`students`.`s_name` AS `s_name`,`checks`.`check_time` AS `check_time` from (((`classes` `c` join `stu_class` `sc` on((`sc`.`c_id` = `c`.`c_id`))) join `students` on((`students`.`s_id` = `sc`.`s_id`))) join `checks` on(((`checks`.`c_id` = `c`.`c_id`) and (`checks`.`s_id` = `students`.`s_id`))));
SET FOREIGN_KEY_CHECKS = 1;
创建视图方便查询：具体代码可以结合Java项目中DAO包的代码。
--1 给某个学生记录 某天的考勤信息（增）
INSERT INTO checks (s_id,c_id,check_time) VALUES (2017010101,01,'2020-01-22 11:01:54');
SELECT CURRENT_TIME();
SELECT NOW();
--2 查询某个班的 某天的所有考勤信息（查）
SELECT c.c_id,c.c_name,students.s_id,students.s_name,checks.check_time
FROM classes c
INNER JOIN stu_class sc ON sc.c_id = c.c_id
INNER JOIN students ON students.s_id = sc.s_id
INNER JOIN checks on checks.c_id = c.c_id AND checks.s_id = students.s_id
WHERE c.c_name='计科一班' AND checks.check_time LIKE '%2020-02-13%';
CREATE VIEW v_class_check AS
SELECT c.c_id,c.c_name,students.s_id,students.s_name,checks.check_time
FROM classes c
INNER JOIN stu_class sc ON sc.c_id = c.c_id
INNER JOIN students ON students.s_id = sc.s_id
INNER JOIN checks on checks.c_id = c.c_id AND checks.s_id = students.s_id
SELECT * FROM v_class_check WHERE c_name ='计科一班' AND check_time LIKE '%2020-02-17%';
--3 查某个学生 2 月的所有考勤情况（查）
SELECT students.s_id, students.s_name, c.c_name, checks.check_time
FROM students
INNER JOIN stu_class sc ON students.s_id = sc.s_id
INNER JOIN classes c ON sc.c_id = c.c_id
INNER JOIN checks ON checks.s_id = students.s_id AND checks.c_id = c.c_id
CREATE VIEW select_stu_2month AS
SELECT students.s_id, students.s_name, c.c_name, checks.check_time
FROM students
INNER JOIN stu_class sc ON students.s_id = sc.s_id
INNER JOIN classes c ON sc.c_id = c.c_id
INNER JOIN checks ON checks.s_id = students.s_id AND checks.c_id = c.c_id
SELECT * FROM select_stu_2month WHERE s_name = '张三' AND check_time LIKE '%2020-02%';
SQL表结构
5. 结语
如果读者有什么不明白的可以私聊或者评论，看到了都会耐心仔细回复。
学而不思则罔，思而不学则殆。共勉！
具体项目代码可以移步我的码云