内容目录

1.Navicat使用

2.pycharm使用数据库

一、Navicat使用

#1. 测试+链接数据库
#2. 新建库
#3. 新建表，新增字段+类型+约束
#4. 设计表：外键
#5. 新建查询
#6. 建立表模型#注意：
批量加注释：ctrl+？键
批量去注释：ctrl+shift+？键

1.1 导出的sql语句代码

代码附在最后

1.2 导入数据库

"""
使用说明：
拷贝上述代码，新建一个.sql文件，保存到桌面打开navicat新建数据库day41，选中新建的数据库鼠标右键选择运行SQL文件弹出文件框，选中刚刚保存到桌面的.sql文件即可
"""
# 快速建表
"""
#准备表、记录  >>> 命令行
mysql> create database db1;
mysql> use db1;
mysql> source /root/init.sql# navicat建表
"""

"""
练习题：
1、查询所有的课程的名称以及对应的任课老师姓名
4、查询平均成绩大于八十分的同学的姓名和平均成绩
7、 查询没有报李平老师课的学生姓名
8、 查询没有同时选修物理课程和体育课程的学生姓名
9、 查询挂科超过两门(包括两门)的学生姓名和班级
"""

二、pycharm使用MySQL

2.1 pycharm使用mysql

pymysql 模块# 1.安装:pip3 insatll pymysql# 2.代码链接import pymysql#链接conn=pymysql.connect(host='localhost',user='root',password='123',database='day41',charset='utf8')#游标cursor=conn.cursor() #执行完毕返回的结果集默认以元组显示#cursor=conn.cursor(cursor=pymysql.cursors.DictCursor)  # 以字典的方式显示数据# 3.pymysql操作数据库#执行sql语句user = input(">>>:").strip()pwd = input(">>>:").strip()sql='select * from userinfo where name="%s" and password="%s"' %(user,pwd) #注意%s需要加引号rows=cursor.execute(sql) #执行sql语句，返回sql查询成功的记录数目# 获取真实数据cursor.fetchone(),cursor.fetchall(),cursor.fetchmany(),类似管道取值，获取一条，所有，多条cursor.scroll(1,'relative')  # 相对移动cursor.scroll(3,'absolute')  # 绝对移动cursor.close()conn.close()

2.2 sql注入问题

# 不要手动去拼接查询的sql语句username = input(">>>:").strip()password = input(">>>:").strip()sql = "select * from user where username='%s' and password='%s'"%(username,password)# 用户名正确username >>>: jason' -- jjsakfjjdkjjkjs
# 用户名密码都不对的情况username >>>: xxx' or 1=1 --asdjkdklqwjdjkjasdljadpassword >>>: ''

2.3 pycharm 对数据库增删改查

"""
# 增
sql = "insert into user(username,password) values(%s,%s)"
rows = cursor.excute(sql,('jason','123'))# 修改
sql = "update user set username='jasonDSB' where id=1"
rows = cursor.excute(sql)增和改单单执行excute并不会真正影响到数据，需要再执行conn.commit()才可以完成真正的增改# 一次插入多行记录
res = cursor,excutemany(sql,[(),(),()]
"""

------------------------------------------------------------------------------------------------------------------------

附在最后的代码：a.sql

/*数据导入：Navicat Premium Data TransferSource Server         : localhostSource Server Type    : MySQLSource Server Version : 50624Source Host           : localhostSource Database       : sqlexamTarget Server Type    : MySQLTarget Server Version : 50624File Encoding         : utf-8Date: 10/21/2016 06:46:46 AM
*/SET NAMES utf8;
SET FOREIGN_KEY_CHECKS = 0;-- ----------------------------
--  Table structure for `class`
-- ----------------------------
DROP TABLE IF EXISTS `class`;
CREATE TABLE `class` (`cid` int(11) NOT NULL AUTO_INCREMENT,`caption` varchar(32) NOT NULL,PRIMARY KEY (`cid`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;-- ----------------------------
--  Records of `class`
-- ----------------------------
BEGIN;
INSERT INTO `class` VALUES ('1', '三年二班'), ('2', '三年三班'), ('3', '一年二班'), ('4', '二年九班');
COMMIT;-- ----------------------------
--  Table structure for `course`
-- ----------------------------
DROP TABLE IF EXISTS `course`;
CREATE TABLE `course` (`cid` int(11) NOT NULL AUTO_INCREMENT,`cname` varchar(32) NOT NULL,`teacher_id` int(11) NOT NULL,PRIMARY KEY (`cid`),KEY `fk_course_teacher` (`teacher_id`),CONSTRAINT `fk_course_teacher` FOREIGN KEY (`teacher_id`) REFERENCES `teacher` (`tid`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;-- ----------------------------
--  Records of `course`
-- ----------------------------
BEGIN;
INSERT INTO `course` VALUES ('1', '生物', '1'), ('2', '物理', '2'), ('3', '体育', '3'), ('4', '美术', '2');
COMMIT;-- ----------------------------
--  Table structure for `score`
-- ----------------------------
DROP TABLE IF EXISTS `score`;
CREATE TABLE `score` (`sid` int(11) NOT NULL AUTO_INCREMENT,`student_id` int(11) NOT NULL,`course_id` int(11) NOT NULL,`num` int(11) NOT NULL,PRIMARY KEY (`sid`),KEY `fk_score_student` (`student_id`),KEY `fk_score_course` (`course_id`),CONSTRAINT `fk_score_course` FOREIGN KEY (`course_id`) REFERENCES `course` (`cid`),CONSTRAINT `fk_score_student` FOREIGN KEY (`student_id`) REFERENCES `student` (`sid`)
) ENGINE=InnoDB AUTO_INCREMENT=53 DEFAULT CHARSET=utf8;-- ----------------------------
--  Records of `score`
-- ----------------------------
BEGIN;
INSERT INTO `score` VALUES ('1', '1', '1', '10'), ('2', '1', '2', '9'), ('5', '1', '4', '66'), ('6', '2', '1', '8'), ('8', '2', '3', '68'), ('9', '2', '4', '99'), ('10', '3', '1', '77'), ('11', '3', '2', '66'), ('12', '3', '3', '87'), ('13', '3', '4', '99'), ('14', '4', '1', '79'), ('15', '4', '2', '11'), ('16', '4', '3', '67'), ('17', '4', '4', '100'), ('18', '5', '1', '79'), ('19', '5', '2', '11'), ('20', '5', '3', '67'), ('21', '5', '4', '100'), ('22', '6', '1', '9'), ('23', '6', '2', '100'), ('24', '6', '3', '67'), ('25', '6', '4', '100'), ('26', '7', '1', '9'), ('27', '7', '2', '100'), ('28', '7', '3', '67'), ('29', '7', '4', '88'), ('30', '8', '1', '9'), ('31', '8', '2', '100'), ('32', '8', '3', '67'), ('33', '8', '4', '88'), ('34', '9', '1', '91'), ('35', '9', '2', '88'), ('36', '9', '3', '67'), ('37', '9', '4', '22'), ('38', '10', '1', '90'), ('39', '10', '2', '77'), ('40', '10', '3', '43'), ('41', '10', '4', '87'), ('42', '11', '1', '90'), ('43', '11', '2', '77'), ('44', '11', '3', '43'), ('45', '11', '4', '87'), ('46', '12', '1', '90'), ('47', '12', '2', '77'), ('48', '12', '3', '43'), ('49', '12', '4', '87'), ('52', '13', '3', '87');
COMMIT;-- ----------------------------
--  Table structure for `student`
-- ----------------------------
DROP TABLE IF EXISTS `student`;
CREATE TABLE `student` (`sid` int(11) NOT NULL AUTO_INCREMENT,`gender` char(1) NOT NULL,`class_id` int(11) NOT NULL,`sname` varchar(32) NOT NULL,PRIMARY KEY (`sid`),KEY `fk_class` (`class_id`),CONSTRAINT `fk_class` FOREIGN KEY (`class_id`) REFERENCES `class` (`cid`)
) ENGINE=InnoDB AUTO_INCREMENT=17 DEFAULT CHARSET=utf8;-- ----------------------------
--  Records of `student`
-- ----------------------------
BEGIN;
INSERT INTO `student` VALUES ('1', '男', '1', '理解'), ('2', '女', '1', '钢蛋'), ('3', '男', '1', '张三'), ('4', '男', '1', '张一'), ('5', '女', '1', '张二'), ('6', '男', '1', '张四'), ('7', '女', '2', '铁锤'), ('8', '男', '2', '李三'), ('9', '男', '2', '李一'), ('10', '女', '2', '李二'), ('11', '男', '2', '李四'), ('12', '女', '3', '如花'), ('13', '男', '3', '刘三'), ('14', '男', '3', '刘一'), ('15', '女', '3', '刘二'), ('16', '男', '3', '刘四');
COMMIT;-- ----------------------------
--  Table structure for `teacher`
-- ----------------------------
DROP TABLE IF EXISTS `teacher`;
CREATE TABLE `teacher` (`tid` int(11) NOT NULL AUTO_INCREMENT,`tname` varchar(32) NOT NULL,PRIMARY KEY (`tid`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;-- ----------------------------
--  Records of `teacher`
-- ----------------------------
BEGIN;
INSERT INTO `teacher` VALUES ('1', '张磊老师'), ('2', '李平老师'), ('3', '刘海燕老师'), ('4', '朱云海老师'), ('5', '李杰老师');
COMMIT;SET FOREIGN_KEY_CHECKS = 1;