MySQL數據庫 -- Navicat、pycharm連接數據庫

內容目錄

1.Navicat使用

2.pycharm使用數據庫

一、Navicat使用

#1. 測試+鏈接數據庫
#2. 新建庫
#3. 新建表，新增字段+類型+約束
#4. 設計表：外鍵
#5. 新建查詢
#6. 建立表模型

#注意：
批量加注釋：ctrl+？鍵
批量去注釋：ctrl+shift+？鍵

1.1 導出的sql語句代碼

代碼附在最后

1.2 導入數據庫

"""
使用說明：
拷貝上述代碼，新建一個.sql文件，保存到桌面

打開navicat新建數據庫day41，選中新建的數據庫鼠標右鍵選擇運行SQL文件

彈出文件框，選中剛剛保存到桌面的.sql文件即可
"""
# 快速建表
"""
#准備表、記錄  >>> 命令行
mysql> create database db1;
mysql> use db1;
mysql> source /root/init.sql

# navicat建表
"""

"""
練習題：
1、查詢所有的課程的名稱以及對應的任課老師姓名
4、查詢平均成績大於八十分的同學的姓名和平均成績
7、 查詢沒有報李平老師課的學生姓名
8、 查詢沒有同時選修物理課程和體育課程的學生姓名
9、 查詢掛科超過兩門(包括兩門)的學生姓名和班級
"""

二、pycharm使用MySQL

2.1 pycharm使用mysql

pymysql 模塊

# 1.安裝:pip3 insatll pymysql

# 2.代碼鏈接
    import pymysql
    #鏈接
    conn=pymysql.connect(
      host='localhost',
      user='root',
      password='123',
      database='day41',
      charset='utf8')
    #游標
    cursor=conn.cursor() #執行完畢返回的結果集默認以元組顯示
    #cursor=conn.cursor(cursor=pymysql.cursors.DictCursor)  # 以字典的方式顯示數據

# 3.pymysql操作數據庫
    #執行sql語句
    user = input(">>>:").strip()
    pwd = input(">>>:").strip()
    sql='select * from userinfo where name="%s" and password="%s"' %(user,pwd) #注意%s需要加引號
    
    rows=cursor.execute(sql) #執行sql語句，返回sql查詢成功的記錄數目
    # 獲取真實數據cursor.fetchone(),cursor.fetchall(),cursor.fetchmany(),類似管道取值，獲取一條，所有，多條
    
    cursor.scroll(1,'relative')  # 相對移動
    cursor.scroll(3,'absolute')  # 絕對移動
    
    cursor.close()
    conn.close()

2.2 sql注入問題

# 不要手動去拼接查詢的sql語句
    username = input(">>>:").strip()
    password = input(">>>:").strip()
    sql = "select * from user where username='%s' and password='%s'"%(username,password)

# 用戶名正確
    username >>>: jason' -- jjsakfjjdkjjkjs
# 用戶名密碼都不對的情況
    username >>>: xxx' or 1=1 --asdjkdklqwjdjkjasdljad
    password >>>: ''

2.3 pycharm 對數據庫增刪改查

"""
# 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)


增和改單單執行excute並不會真正影響到數據，需要再執行conn.commit()才可以完成真正的增改


# 一次插入多行記錄
res = cursor,excutemany(sql,[(),(),()]
"""

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

附在最后的代碼：a.sql

/*
 數據導入：
 Navicat Premium Data Transfer

 Source Server         : localhost
 Source Server Type    : MySQL
 Source Server Version : 50624
 Source Host           : localhost
 Source Database       : sqlexam

 Target Server Type    : MySQL
 Target Server Version : 50624
 File Encoding         : utf-8

 Date: 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', '體育', '3'), ('4', '美術', '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', '鋼蛋'), ('3', '男', '1', '張三'), ('4', '男', '1', '張一'), ('5', '女', '1', '張二'), ('6', '男', '1', '張四'), ('7', '女', '2', '鐵錘'), ('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', '劉三'), ('14', '男', '3', '劉一'), ('15', '女', '3', '劉二'), ('16', '男', '3', '劉四');
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', '張磊老師'), ('2', '李平老師'), ('3', '劉海燕老師'), ('4', '朱雲海老師'), ('5', '李傑老師');
COMMIT;

SET FOREIGN_KEY_CHECKS = 1;