MySQL数据库，从入门到精通：第一篇——MySQL概念详解
练习SQL 数据库代码：第一篇_MySQL概念详解1. 为什么要使用数据库2. 数据库与数据库管理系统2.1 数据库的相关概念2.2 数据库与数据库管理系统的关系2.3 常见的数据库管理系统排名(DBMS)2.4 常见的数据库介绍 3. MySQL介绍3.1 概述3.2 MySQL发展史重大事件3.3 关于MySQL 8.03.4 Oracle vs MySQL目录层级
MySQL数据库，从入门到精通：第一篇——MySQL概念详解
MySQL数据库，从入门到精通：第二篇——MySQL关系型数据库与非关系型数据库的比较
MySQL数据库，从入门到精通：第三篇——MySQL 数据库规范和基础查询语句
MySQL数据库，从入门到精通：第四篇——MySQL中常用的运算符及其用法
MySQL数据库，从入门到精通：第五篇——MySQL排序和分页
MySQL数据库，从入门到精通：第六篇——全面掌握MySQL多表查询技巧
MySQL数据库，从入门到精通：第七篇——MySQL单行函数应用
MySQL数据库，从入门到精通：第八篇——MySQL聚合函数实战探究：优化SELECT过程助力高效查询
MySQL数据库，从入门到精通：第九篇——MySQL子查询
MySQL数据库，从入门到精通：第十篇——MySQL表创建和管理指南
MySQL数据库，从入门到精通：第十一篇——MySQL数据处理之增删改指南
MySQL数据库，从入门到精通：第十二篇——MySQL数据类型详解
MySQL数据库，从入门到精通：第十三篇——MySQL数据表约束详解
MySQL数据库，从入门到精通：第十四篇——MySQL视图详解
MySQL数据库，从入门到精通：第十五篇——MySQL存储过程和函数详解
MySQL数据库，从入门到精通：第十六篇——MySQL变量、流程控制和游标详解
MySQL数据库，从入门到精通：第十七篇——MySQL 触发器的使用方法及注意事项
MySQL数据库，从入门到精通：第十八篇——MySQL 8新特性全解析
THIS IS END!
练习SQL 数据库代码：
/*SQLyog Ultimate v12.08 (64 bit)MySQL - 5.7.28-log : Database - atguigudb**********************************************************************//*!40101 SET NAMES utf8 */;/*!40101 SET SQL_MODE=''*/;/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;CREATE DATABASE /*!32312 IF NOT EXISTS*/`atguigudb` /*!40100 DEFAULT CHARACTER SET utf8 */;USE `atguigudb`;/*Table structure for table `countries` */DROP TABLE IF EXISTS `countries`;CREATE TABLE `countries` (`country_id` char(2) NOT NULL,`country_name` varchar(40) DEFAULT NULL,`region_id` int(11) DEFAULT NULL,PRIMARY KEY (`country_id`),KEY `countr_reg_fk` (`region_id`),CONSTRAINT `countr_reg_fk` FOREIGN KEY (`region_id`) REFERENCES `regions` (`region_id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;/*Data for the table `countries` */insert into `countries`(`country_id`,`country_name`,`region_id`) values ('AR','Argentina',2),('AU','Australia',3),('BE','Belgium',1),('BR','Brazil',2),('CA','Canada',2),('CH','Switzerland',1),('CN','China',3),('DE','Germany',1),('DK','Denmark',1),('EG','Egypt',4),('FR','France',1),('HK','HongKong',3),('IL','Israel',4),('IN','India',3),('IT','Italy',1),('JP','Japan',3),('KW','Kuwait',4),('MX','Mexico',2),('NG','Nigeria',4),('NL','Netherlands',1),('SG','Singapore',3),('UK','United Kingdom',1),('US','United States of America',2),('ZM','Zambia',4),('ZW','Zimbabwe',4);/*Table structure for table `departments` */DROP TABLE IF EXISTS `departments`;CREATE TABLE `departments` (`department_id` int(4) NOT NULL DEFAULT '0',`department_name` varchar(30) NOT NULL,`manager_id` int(6) DEFAULT NULL,`location_id` int(4) DEFAULT NULL,PRIMARY KEY (`department_id`),UNIQUE KEY `dept_id_pk` (`department_id`),KEY `dept_loc_fk` (`location_id`),KEY `dept_mgr_fk` (`manager_id`),CONSTRAINT `dept_loc_fk` FOREIGN KEY (`location_id`) REFERENCES `locations` (`location_id`),CONSTRAINT `dept_mgr_fk` FOREIGN KEY (`manager_id`) REFERENCES `employees` (`employee_id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;/*Data for the table `departments` */insert into `departments`(`department_id`,`department_name`,`manager_id`,`location_id`) values (10,'Administration',200,1700),(20,'Marketing',201,1800),(30,'Purchasing',114,1700),(40,'Human Resources',203,2400),(50,'Shipping',121,1500),(60,'IT',103,1400),(70,'Public Relations',204,2700),(80,'Sales',145,2500),(90,'Executive',100,1700),(100,'Finance',108,1700),(110,'Accounting',205,1700),(120,'Treasury',NULL,1700),(130,'Corporate Tax',NULL,1700),(140,'Control And Credit',NULL,1700),(150,'Shareholder Services',NULL,1700),(160,'Benefits',NULL,1700),(170,'Manufacturing',NULL,1700),(180,'Construction',NULL,1700),(190,'Contracting',NULL,1700),(200,'Operations',NULL,1700),(210,'IT Support',NULL,1700),(220,'NOC',NULL,1700),(230,'IT Helpdesk',NULL,1700),(240,'Government Sales',NULL,1700),(250,'Retail Sales',NULL,1700),(260,'Recruiting',NULL,1700),(270,'Payroll',NULL,1700);/*Table structure for table `employees` */DROP TABLE IF EXISTS `employees`;CREATE TABLE `employees` (`employee_id` int(6) NOT NULL DEFAULT '0',`first_name` varchar(20) DEFAULT NULL,`last_name` varchar(25) NOT NULL,`email` varchar(25) NOT NULL,`phone_number` varchar(20) DEFAULT NULL,`hire_date` date NOT NULL,`job_id` varchar(10) NOT NULL,`salary` double(8,2) DEFAULT NULL,`commission_pct` double(2,2) DEFAULT NULL,`manager_id` int(6) DEFAULT NULL,`department_id` int(4) DEFAULT NULL,PRIMARY KEY (`employee_id`),UNIQUE KEY `emp_email_uk` (`email`),UNIQUE KEY `emp_emp_id_pk` (`employee_id`),KEY `emp_dept_fk` (`department_id`),KEY `emp_job_fk` (`job_id`),KEY `emp_manager_fk` (`manager_id`),CONSTRAINT `emp_dept_fk` FOREIGN KEY (`department_id`) REFERENCES `departments` (`department_id`),CONSTRAINT `emp_job_fk` FOREIGN KEY (`job_id`) REFERENCES `jobs` (`job_id`),CONSTRAINT `emp_manager_fk` FOREIGN KEY (`manager_id`) REFERENCES `employees` (`employee_id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;/*Data for the table `employees` */insert into `employees`(`employee_id`,`first_name`,`last_name`,`email`,`phone_number`,`hire_date`,`job_id`,`salary`,`commission_pct`,`manager_id`,`department_id`) values (100,'Steven','King','SKING','515.123.4567','1987-06-17','AD_PRES',24000.00,NULL,NULL,90),(101,'Neena','Kochhar','NKOCHHAR','515.123.4568','1989-09-21','AD_VP',17000.00,NULL,100,90),(102,'Lex','De Haan','LDEHAAN','515.123.4569','1993-01-13','AD_VP',17000.00,NULL,100,90),(103,'Alexander','Hunold','AHUNOLD','590.423.4567','1990-01-03','IT_PROG',9000.00,NULL,102,60),(104,'Bruce','Ernst','BERNST','590.423.4568','1991-05-21','IT_PROG',6000.00,NULL,103,60),(105,'David','Austin','DAUSTIN','590.423.4569','1997-06-25','IT_PROG',4800.00,NULL,103,60),(106,'Valli','Pataballa','VPATABAL','590.423.4560','1998-02-05','IT_PROG',4800.00,NULL,103,60),(107,'Diana','Lorentz','DLORENTZ','590.423.5567','1999-02-07','IT_PROG',4200.00,NULL,103,60),(108,'Nancy','Greenberg','NGREENBE','515.124.4569','1994-08-17','FI_MGR',12000.00,NULL,101,100),(109,'Daniel','Faviet','DFAVIET','515.124.4169','1994-08-16','FI_ACCOUNT',9000.00,NULL,108,100),(110,'John','Chen','JCHEN','515.124.4269','1997-09-28','FI_ACCOUNT',8200.00,NULL,108,100),(111,'Ismael','Sciarra','ISCIARRA','515.124.4369','1997-09-30','FI_ACCOUNT',7700.00,NULL,108,100),(112,'Jose Manuel','Urman','JMURMAN','515.124.4469','1998-03-07','FI_ACCOUNT',7800.00,NULL,108,100),(113,'Luis','Popp','LPOPP','515.124.4567','1999-12-07','FI_ACCOUNT',6900.00,NULL,108,100),(114,'Den','Raphaely','DRAPHEAL','515.127.4561','1994-12-07','PU_MAN',11000.00,NULL,100,30),(115,'Alexander','Khoo','AKHOO','515.127.4562','1995-05-18','PU_CLERK',3100.00,NULL,114,30),(116,'Shelli','Baida','SBAIDA','515.127.4563','1997-12-24','PU_CLERK',2900.00,NULL,114,30),(117,'Sigal','Tobias','STOBIAS','515.127.4564','1997-07-24','PU_CLERK',2800.00,NULL,114,30),(118,'Guy','Himuro','GHIMURO','515.127.4565','1998-11-15','PU_CLERK',2600.00,NULL,114,30),(119,'Karen','Colmenares','KCOLMENA','515.127.4566','1999-08-10','PU_CLERK',2500.00,NULL,114,30),(120,'Matthew','Weiss','MWEISS','650.123.1234','1996-07-18','ST_MAN',8000.00,NULL,100,50),(121,'Adam','Fripp','AFRIPP','650.123.2234','1997-04-10','ST_MAN',8200.00,NULL,100,50),(122,'Payam','Kaufling','PKAUFLIN','650.123.3234','1995-05-01','ST_MAN',7900.00,NULL,100,50),(123,'Shanta','Vollman','SVOLLMAN','650.123.4234','1997-10-10','ST_MAN',6500.00,NULL,100,50),(124,'Kevin','Mourgos','KMOURGOS','650.123.5234','1999-11-16','ST_MAN',5800.00,NULL,100,50),(125,'Julia','Nayer','JNAYER','650.124.1214','1997-07-16','ST_CLERK',3200.00,NULL,120,50),(126,'Irene','Mikkilineni','IMIKKILI','650.124.1224','1998-09-28','ST_CLERK',2700.00,NULL,120,50),(127,'James','Landry','JLANDRY','650.124.1334','1999-01-14','ST_CLERK',2400.00,NULL,120,50),(128,'Steven','Markle','SMARKLE','650.124.1434','2000-03-08','ST_CLERK',2200.00,NULL,120,50),(129,'Laura','Bissot','LBISSOT','650.124.5234','1997-08-20','ST_CLERK',3300.00,NULL,121,50),(130,'Mozhe','Atkinson','MATKINSO','650.124.6234','1997-10-30','ST_CLERK',2800.00,NULL,121,50),(131,'James','Marlow','JAMRLOW','650.124.7234','1997-02-16','ST_CLERK',2500.00,NULL,121,50),(132,'TJ','Olson','TJOLSON','650.124.8234','1999-04-10','ST_CLERK',2100.00,NULL,121,50),(133,'Jason','Mallin','JMALLIN','650.127.1934','1996-06-14','ST_CLERK',3300.00,NULL,122,50),(134,'Michael','Rogers','MROGERS','650.127.1834','1998-08-26','ST_CLERK',2900.00,NULL,122,50),(135,'Ki','Gee','KGEE','650.127.1734','1999-12-12','ST_CLERK',2400.00,NULL,122,50),(136,'Hazel','Philtanker','HPHILTAN','650.127.1634','2000-02-06','ST_CLERK',2200.00,NULL,122,50),(137,'Renske','Ladwig','RLADWIG','650.121.1234','1995-07-14','ST_CLERK',3600.00,NULL,123,50),(138,'Stephen','Stiles','SSTILES','650.121.2034','1997-10-26','ST_CLERK',3200.00,NULL,123,50),(139,'John','Seo','JSEO','650.121.','1998-02-12','ST_CLERK',2700.00,NULL,123,50),(140,'Joshua','Patel','JPATEL','650.121.1834','1998-04-06','ST_CLERK',2500.00,NULL,123,50),(141,'Trenna','Rajs','TRAJS','650.121.8009','1995-10-17','ST_CLERK',3500.00,NULL,124,50),(142,'Curtis','Davies','CDAVIES','650.121.2994','1997-01-29','ST_CLERK',3100.00,NULL,124,50),(143,'Randall','Matos','RMATOS','650.121.2874','1998-03-15','ST_CLERK',2600.00,NULL,124,50),(144,'Peter','Vargas','PVARGAS','650.121.','1998-07-09','ST_CLERK',2500.00,NULL,124,50),(145,'John','Russell','JRUSSEL','011.44.1344.429268','1996-10-01','SA_MAN',14000.00,0.40,100,80),(146,'Karen','Partners','KPARTNER','011.44.1344.467268','1997-01-05','SA_MAN',13500.00,0.30,100,80),(147,'Alberto','Errazuriz','AERRAZUR','011.44.1344.429278','1997-03-10','SA_MAN',12000.00,0.30,100,80),(148,'Gerald','Cambrault','GCAMBRAU','011.44.1344.619268','1999-10-15','SA_MAN',11000.00,0.30,100,80),(149,'Eleni','Zlotkey','EZLOTKEY','011.44.1344.429018','2000-01-29','SA_MAN',10500.00,0.20,100,80),(150,'Peter','Tucker','PTUCKER','011.44.1344.129268','1997-01-30','SA_REP',10000.00,0.30,145,80),(151,'David','Bernstein','DBERNSTE','011.44.1344.345268','1997-03-24','SA_REP',9500.00,0.25,145,80),(152,'Peter','Hall','PHALL','011.44.1344.478968','1997-08-20','SA_REP',9000.00,0.25,145,80),(153,'Christopher','Olsen','COLSEN','011.44.1344.498718','1998-03-30','SA_REP',8000.00,0.20,145,80),(154,'Nanette','Cambrault','NCAMBRAU','011.44.1344.987668','1998-12-09','SA_REP',7500.00,0.20,145,80),(155,'Oliver','Tuvault','OTUVAULT','011.44.1344.486508','1999-11-23','SA_REP',7000.00,0.15,145,80),(156,'Janette','King','JKING','011.44.1345.429268','1996-01-30','SA_REP',10000.00,0.35,146,80),(157,'Patrick','Sully','PSULLY','011.44.1345.929268','1996-03-04','SA_REP',9500.00,0.35,146,80),(158,'Allan','McEwen','AMCEWEN','011.44.1345.829268','1996-08-01','SA_REP',9000.00,0.35,146,80),(159,'Lindsey','Smith','LSMITH','011.44.1345.729268','1997-03-10','SA_REP',8000.00,0.30,146,80),(160,'Louise','Doran','LDORAN','011.44.1345.629268','1997-12-15','SA_REP',7500.00,0.30,146,80),(161,'Sarath','Sewall','SSEWALL','011.44.1345.529268','1998-11-03','SA_REP',7000.00,0.25,146,80),(162,'Clara','Vishney','CVISHNEY','011.44.1346.129268','1997-11-11','SA_REP',10500.00,0.25,147,80),(163,'Danielle','Greene','DGREENE','011.44.1346.229268','1999-03-19','SA_REP',9500.00,0.15,147,80),(164,'Mattea','Marvins','MMARVINS','011.44.1346.329268','2000-01-24','SA_REP',7200.00,0.10,147,80),(165,'David','Lee','DLEE','011.44.1346.529268','2000-02-23','SA_REP',6800.00,0.10,147,80),(166,'Sundar','Ande','SANDE','011.44.1346.629268','2000-03-24','SA_REP',6400.00,0.10,147,80),(167,'Amit','Banda','ABANDA','011.44.1346.729268','2000-04-21','SA_REP',6200.00,0.10,147,80),(168,'Lisa','Ozer','LOZER','011.44.1343.929268','1997-03-11','SA_REP',11500.00,0.25,148,80),(169,'Harrison','Bloom','HBLOOM','011.44.1343.829268','1998-03-23','SA_REP',10000.00,0.20,148,80),(170,'Tayler','Fox','TFOX','011.44.1343.729268','1998-01-24','SA_REP',9600.00,0.20,148,80),(171,'William','Smith','WSMITH','011.44.1343.629268','1999-02-23','SA_REP',7400.00,0.15,148,80),(172,'Elizabeth','Bates','EBATES','011.44.1343.529268','1999-03-24','SA_REP',7300.00,0.15,148,80),(173,'Sundita','Kumar','SKUMAR','011.44.1343.329268','2000-04-21','SA_REP',6100.00,0.10,148,80),(174,'Ellen','Abel','EABEL','011.44.1644.429267','1996-05-11','SA_REP',11000.00,0.30,149,80),(175,'Alyssa','Hutton','AHUTTON','011.44.1644.429266','1997-03-19','SA_REP',8800.00,0.25,149,80),(176,'Jonathon','Taylor','JTAYLOR','011.44.1644.429265','1998-03-24','SA_REP',8600.00,0.20,149,80),(177,'Jack','Livingston','JLIVINGS','011.44.1644.429264','1998-04-23','SA_REP',8400.00,0.20,149,80),(178,'Kimberely','Grant','KGRANT','011.44.1644.429263','1999-05-24','SA_REP',7000.00,0.15,149,NULL),(179,'Charles','Johnson','CJOHNSON','011.44.1644.429262','2000-01-04','SA_REP',6200.00,0.10,149,80),(180,'Winston','Taylor','WTAYLOR','650.507.9876','1998-01-24','SH_CLERK',3200.00,NULL,120,50),(181,'Jean','Fleaur','JFLEAUR','650.507.9877','1998-02-23','SH_CLERK',3100.00,NULL,120,50),(182,'Martha','Sullivan','MSULLIVA','650.507.9878','1999-06-21','SH_CLERK',2500.00,NULL,120,50),(183,'Girard','Geoni','GGEONI','650.507.9879','2000-02-03','SH_CLERK',2800.00,NULL,120,50),(184,'Nandita','Sarchand','NSARCHAN','650.509.1876','1996-01-27','SH_CLERK',4200.00,NULL,121,50),(185,'Alexis','Bull','ABULL','650.509.2876','1997-02-20','SH_CLERK',4100.00,NULL,121,50),(186,'Julia','Dellinger','JDELLING','650.509.3876','1998-06-24','SH_CLERK',3400.00,NULL,121,50),(187,'Anthony','Cabrio','ACABRIO','650.509.4876','1999-02-07','SH_CLERK',3000.00,NULL,121,50),(188,'Kelly','Chung','KCHUNG','650.505.1876','1997-06-14','SH_CLERK',3800.00,NULL,122,50),(189,'Jennifer','Dilly','JDILLY','650.505.2876','1997-08-13','SH_CLERK',3600.00,NULL,122,50),(190,'Timothy','Gates','TGATES','650.505.3876','1998-07-11','SH_CLERK',2900.00,NULL,122,50),(191,'Randall','Perkins','RPERKINS','650.505.4876','1999-12-19','SH_CLERK',2500.00,NULL,122,50),(192,'Sarah','Bell','SBELL','650.501.1876','1996-02-04','SH_CLERK',4000.00,NULL,123,50),(193,'Britney','Everett','BEVERETT','650.501.2876','1997-03-03','SH_CLERK',3900.00,NULL,123,50),(194,'Samuel','McCain','SMCCAIN','650.501.3876','1998-07-01','SH_CLERK',3200.00,NULL,123,50),(195,'Vance','Jones','VJONES','650.501.4876','1999-03-17','SH_CLERK',2800.00,NULL,123,50),(196,'Alana','Walsh','AWALSH','650.507.9811','1998-04-24','SH_CLERK',3100.00,NULL,124,50),(197,'Kevin','Feeney','KFEENEY','650.507.9822','1998-05-23','SH_CLERK',3000.00,NULL,124,50),(198,'Donald','OConnell','DOCONNEL','650.507.9833','1999-06-21','SH_CLERK',2600.00,NULL,124,50),(199,'Douglas','Grant','DGRANT','650.507.9844','2000-01-13','SH_CLERK',2600.00,NULL,124,50),(200,'Jennifer','Whalen','JWHALEN','515.123.4444','1987-09-17','AD_ASST',4400.00,NULL,101,10),(201,'Michael','Hartstein','MHARTSTE','515.123.5555','1996-02-17','MK_MAN',13000.00,NULL,100,20),(202,'Pat','Fay','PFAY','603.123.6666','1997-08-17','MK_REP',6000.00,NULL,201,20),(203,'Susan','Mavris','SMAVRIS','515.123.7777','1994-06-07','HR_REP',6500.00,NULL,101,40),(204,'Hermann','Baer','HBAER','515.123.8888','1994-06-07','PR_REP',10000.00,NULL,101,70),(205,'Shelley','Higgins','SHIGGINS','515.123.8080','1994-06-07','AC_MGR',12000.00,NULL,101,110),(206,'William','Gietz','WGIETZ','515.123.8181','1994-06-07','AC_ACCOUNT',8300.00,NULL,205,110);/*Table structure for table `job_grades` */DROP TABLE IF EXISTS `job_grades`;CREATE TABLE `job_grades` (`grade_level` varchar(3) DEFAULT NULL,`lowest_sal` int(11) DEFAULT NULL,`highest_sal` int(11) DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8;/*Data for the table `job_grades` */insert into `job_grades`(`grade_level`,`lowest_sal`,`highest_sal`) values ('A',1000,2999),('B',3000,5999),('C',6000,9999),('D',10000,14999),('E',15000,24999),('F',25000,40000);/*Table structure for table `job_history` */DROP TABLE IF EXISTS `job_history`;CREATE TABLE `job_history` (`employee_id` int(6) NOT NULL,`start_date` date NOT NULL,`end_date` date NOT NULL,`job_id` varchar(10) NOT NULL,`department_id` int(4) DEFAULT NULL,PRIMARY KEY (`employee_id`,`start_date`),UNIQUE KEY `jhist_emp_id_st_date_pk` (`employee_id`,`start_date`),KEY `jhist_job_fk` (`job_id`),KEY `jhist_dept_fk` (`department_id`),CONSTRAINT `jhist_dept_fk` FOREIGN KEY (`department_id`) REFERENCES `departments` (`department_id`),CONSTRAINT `jhist_emp_fk` FOREIGN KEY (`employee_id`) REFERENCES `employees` (`employee_id`),CONSTRAINT `jhist_job_fk` FOREIGN KEY (`job_id`) REFERENCES `jobs` (`job_id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;/*Data for the table `job_history` */insert into `job_history`(`employee_id`,`start_date`,`end_date`,`job_id`,`department_id`) values (101,'1989-09-21','1993-10-27','AC_ACCOUNT',110),(101,'1993-10-28','1997-03-15','AC_MGR',110),(102,'1993-01-13','1998-07-24','IT_PROG',60),(114,'1998-03-24','1999-12-31','ST_CLERK',50),(122,'1999-01-01','1999-12-31','ST_CLERK',50),(176,'1998-03-24','1998-12-31','SA_REP',80),(176,'1999-01-01','1999-12-31','SA_MAN',80),(200,'1987-09-17','1993-06-17','AD_ASST',90),(200,'1994-07-01','1998-12-31','AC_ACCOUNT',90),(201,'1996-02-17','1999-12-19','MK_REP',20);/*Table structure for table `jobs` */DROP TABLE IF EXISTS `jobs`;CREATE TABLE `jobs` (`job_id` varchar(10) NOT NULL DEFAULT '',`job_title` varchar(35) NOT NULL,`min_salary` int(6) DEFAULT NULL,`max_salary` int(6) DEFAULT NULL,PRIMARY KEY (`job_id`),UNIQUE KEY `job_id_pk` (`job_id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;/*Data for the table `jobs` */insert into `jobs`(`job_id`,`job_title`,`min_salary`,`max_salary`) values ('AC_ACCOUNT','Public Accountant',4200,9000),('AC_MGR','Accounting Manager',8200,16000),('AD_ASST','Administration Assistant',3000,6000),('AD_PRES','President',20000,40000),('AD_VP','Administration Vice President',15000,30000),('FI_ACCOUNT','Accountant',4200,9000),('FI_MGR','Finance Manager',8200,16000),('HR_REP','Human Resources Representative',4000,9000),('IT_PROG','Programmer',4000,10000),('MK_MAN','Marketing Manager',9000,15000),('MK_REP','Marketing Representative',4000,9000),('PR_REP','Public Relations Representative',4500,10500),('PU_CLERK','Purchasing Clerk',2500,5500),('PU_MAN','Purchasing Manager',8000,15000),('SA_MAN','Sales Manager',10000,20000),('SA_REP','Sales Representative',6000,12000),('SH_CLERK','Shipping Clerk',2500,5500),('ST_CLERK','Stock Clerk',2000,5000),('ST_MAN','Stock Manager',5500,8500);/*Table structure for table `locations` */DROP TABLE IF EXISTS `locations`;CREATE TABLE `locations` (`location_id` int(4) NOT NULL DEFAULT '0',`street_address` varchar(40) DEFAULT NULL,`postal_code` varchar(12) DEFAULT NULL,`city` varchar(30) NOT NULL,`state_province` varchar(25) DEFAULT NULL,`country_id` char(2) DEFAULT NULL,PRIMARY KEY (`location_id`),UNIQUE KEY `loc_id_pk` (`location_id`),KEY `loc_c_id_fk` (`country_id`),CONSTRAINT `loc_c_id_fk` FOREIGN KEY (`country_id`) REFERENCES `countries` (`country_id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;/*Data for the table `locations` */insert into `locations`(`location_id`,`street_address`,`postal_code`,`city`,`state_province`,`country_id`) values (1000,'1297 Via Cola di Rie','00989','Roma',NULL,'IT'),(1100,'93091 Calle della Testa','10934','Venice',NULL,'IT'),(1200,' Shinjuku-ku','1689','Tokyo','Tokyo Prefecture','JP'),(1300,'9450 Kamiya-cho','6823','Hiroshima',NULL,'JP'),(1400,' Jabberwocky Rd','26192','Southlake','Texas','US'),(1500,' Interiors Blvd','99236','South San Francisco','California','US'),(1600,' Zagora St','50090','South Brunswick','New Jersey','US'),(1700,' Charade Rd','98199','Seattle','Washington','US'),(1800,'147 Spadina Ave','M5V 2L7','Toronto','Ontario','CA'),(1900,'6092 Boxwood St','YSW 9T2','Whitehorse','Yukon','CA'),(2000,'40-5-12 Laogianggen','190518','Beijing',NULL,'CN'),(2100,'1298 Vileparle (E)','490231','Bombay','Maharashtra','IN'),(2200,'12-98 Victoria Street','2901','Sydney','New South Wales','AU'),(2300,'198 Clementi North','540198','Singapore',NULL,'SG'),(2400,'8204 Arthur St',NULL,'London',NULL,'UK'),(2500,'Magdalen Centre, The Oxford Science Park','OX9 9ZB','Oxford','Oxford','UK'),(2600,'9702 Chester Road','09629850293','Stretford','Manchester','UK'),(2700,'Schwanthalerstr. 7031','80925','Munich','Bavaria','DE'),(2800,'Rua Frei Caneca 1360 ','01307-002','Sao Paulo','Sao Paulo','BR'),(2900,'20 Rue des Corps-Saints','1730','Geneva','Geneve','CH'),(3000,'Murtenstrasse 921','3095','Bern','BE','CH'),(3100,'Pieter Breughelstraat 837','3029SK','Utrecht','Utrecht','NL'),(3200,'Mariano Escobedo 9991','11932','Mexico City','Distrito Federal,','MX');/*Table structure for table `order` */DROP TABLE IF EXISTS `order`;CREATE TABLE `order` (`order_id` int(11) DEFAULT NULL,`order_name` varchar(15) DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8;/*Data for the table `order` */insert into `order`(`order_id`,`order_name`) values (1,'shkstart'),(2,'tomcat'),(3,'dubbo');/*Table structure for table `regions` */DROP TABLE IF EXISTS `regions`;CREATE TABLE `regions` (`region_id` int(11) NOT NULL,`region_name` varchar(25) DEFAULT NULL,PRIMARY KEY (`region_id`),UNIQUE KEY `reg_id_pk` (`region_id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;/*Data for the table `regions` */insert into `regions`(`region_id`,`region_name`) values (1,'Europe'),(2,'Americas'),(3,'Asia'),(4,'Middle East and Africa');/*Table structure for table `emp_details_view` */DROP TABLE IF EXISTS `emp_details_view`;/*!50001 DROP VIEW IF EXISTS `emp_details_view` */;/*!50001 DROP TABLE IF EXISTS `emp_details_view` */;/*!50001 CREATE TABLE `emp_details_view`(`employee_id` int(6) ,`job_id` varchar(10) ,`manager_id` int(6) ,`department_id` int(4) ,`location_id` int(4) ,`country_id` char(2) ,`first_name` varchar(20) ,`last_name` varchar(25) ,`salary` double(8,2) ,`commission_pct` double(2,2) ,`department_name` varchar(30) ,`job_title` varchar(35) ,`city` varchar(30) ,`state_province` varchar(25) ,`country_name` varchar(40) ,`region_name` varchar(25) )*/;/*View structure for view emp_details_view *//*!50001 DROP TABLE IF EXISTS `emp_details_view` */;/*!50001 DROP VIEW IF EXISTS `emp_details_view` */;/*!50001 CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `emp_details_view` AS select `e`.`employee_id` AS `employee_id`,`e`.`job_id` AS `job_id`,`e`.`manager_id` AS `manager_id`,`e`.`department_id` AS `department_id`,`d`.`location_id` AS `location_id`,`l`.`country_id` AS `country_id`,`e`.`first_name` AS `first_name`,`e`.`last_name` AS `last_name`,`e`.`salary` AS `salary`,`e`.`commission_pct` AS `commission_pct`,`d`.`department_name` AS `department_name`,`j`.`job_title` AS `job_title`,`l`.`city` AS `city`,`l`.`state_province` AS `state_province`,`c`.`country_name` AS `country_name`,`r`.`region_name` AS `region_name` from (((((`employees` `e` join `departments` `d`) join `jobs` `j`) join `locations` `l`) join `countries` `c`) join `regions` `r`) where ((`e`.`department_id` = `d`.`department_id`) and (`d`.`location_id` = `l`.`location_id`) and (`l`.`country_id` = `c`.`country_id`) and (`c`.`region_id` = `r`.`region_id`) and (`j`.`job_id` = `e`.`job_id`)) */;/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;
前言：本文主要介绍了使用数据库的原因、数据库管理系统以及常见的数据库排名和介绍。特别地，文章详细介绍了MySQL数据库的概念、历史发展和MySQL 8版本的特性，以及Oracle和MySQL之间的差异。希望读者通过本文了解数据库的重要性以及MySQL在互联网企业中的广泛应用。
摘要：本文是一篇针对MySQL数据库介绍的文章，主要围绕数据库和数据库管理系统的概念，介绍了常见的数据库和DBMS以及它们的排名。文章详细探讨了MySQL作为一种关系型数据库管理系统的特性和历史发展，最后对比了Oracle和MySQL之间的不同之处。通过阅读本文，读者可以加深对MySQL数据库的理解和应用，并进一步认识到数据库在企业级应用中的重要性。
第一篇_MySQL概念详解
1. 为什么要使用数据库
持久化(persistence)：把数据保存到可掉电式存储设备中以供之后使用。大多数情况下，特别是企业级应用，数据持久化意味着将内存中的数据保存到硬盘上加以”固化”，而持久化的实现过程大多通过各种关系数据库来完成。
持久化的主要作用是将内存中的数据存储在关系型数据库中，当然也可以存储在磁盘文件、XML数据文件中。
2. 数据库与数据库管理系统
2.1 数据库的相关概念
2.2 数据库与数据库管理系统的关系
数据库管理系统(DBMS)可以管理多个数据库，一般开发人员会针对每一个应用创建一个数据库。为保存
应用中实体的数据，一般会在数据库创建多个表，以保存程序中实体用户的数据。
数据库管理系统、数据库和表的关系如图所示：
2.3 常见的数据库管理系统排名(DBMS)
目前互联网上常见的数据库管理软件有Oracle、MySQL、MS SQL Server、DB2、PostgreSQL、Access、Sybase、Informix这几种。以下是DB-Engines Ranking 对各数据库受欢迎程度进行调查后的统计结果：（查看数据库最新排名: https://db-/en/ranking）
对应的走势图：（https://db-/en/ranking_trend）
2.4 常见的数据库介绍
Oracle
1979 年，Oracle 2 诞生，它是第一个商用的 RDBMS（关系型数据库管理系统）。随着 Oracle
软件的名气越来越大，公司也改名叫 Oracle 公司。 ，总计85亿美金收购BEA Systems。
，总计74亿美金收购SUN。此前的，SUN以10亿美金收购MySQL。意味着Oracle 同时拥有了 MySQL
的管理权，至此 Oracle 在数据库领域中成为绝对的领导者。 ，甲骨文超越IBM，成为继Microsoft后全球第二大软件公司。
如今 Oracle 的年收入达到了 400 亿美金，足以证明商用（收费）数据库软件的价值
SQL Server
SQL Server 是微软开发的大型商业数据库，诞生于 1989
年。C#、.net等语言常使用，与WinNT完全集成，也可以很好地与Microsoft BackOffice产品集成。
DB2
IBM公司的数据库产品,收费的。常应用在银行系统中。
PostgreSQL
PostgreSQL 的稳定性极强，最符合SQL标准，开放源码，具备商业级DBMS质量。PG对数据量大的文本以及SQL处理较快。已经淡出历史舞台。提供了一个非常专业数据建模的工具PowerDesigner。
SQLite
嵌入式的小型数据库，应用在手机端。
零配置，SQlite3不用安装，不用配置，不用启动，关闭或者配置数据库实例。当系统崩溃后不用做任何恢复操作，再下次使用数据库的时候自动恢复。
informix
IBM公司出品，取自Information
和Unix的结合，它是第一个被移植到Linux上的商业数据库产品。运行于unix/linux平台，命令行操作。
性能较高，支持集群，适应于安全性要求极高的系统，尤其是银行，证券系统的应用。
3. MySQL介绍
3.1 概述
MySQL是一个开放源代码的关系型数据库管理系统，由瑞典MySQL AB（创始人Michael
Widenius）公司1995年开发，迅速成为开源数据库的 No.1。
被 Sun 收购（10亿美金），Sun被Oracle 收购。 MariaDB 应运而生。（MySQL 的创 造者担心 MySQL 有闭源的风险，因此创建了 MySQL 的分支项目 MariaDB） MySQL6.x 版本之后分为 社区版 和 商业版 。
MySQL是一种关联数据库管理系统，将数据保存在不同的表中，而不是将所有数据放在一个大仓库 内，这样就增加了速度并提高了灵活性。
MySQL是开源的，所以你不需要支付额外的费用。
MySQL是可以定制的，采用了 GPL（GNU General Public License） 协议，你可以修改源码来 开发自己的MySQL系统。 MySQL支持大型的数据库。可以处理拥有上千万条记录的大型数据库。
MySQL支持大型数据库，支持5000万条记录的数据仓库，32位系统表文件最大可支持 4GB ，64位系统支持最大的表文件为 8TB 。
MySQL使用 标准的SQL数据语言 形式。
MySQL可以允许运行于多个系统上，并且支持多种语言。这些编程语言包括C、C++、Python、 Java、Perl、PHP和Ruby等。
3.2 MySQL发展史重大事件
MySQL的历史就是整个互联网的发展史。互联网业务从社交领域、电商领域到金融领域的发展，推动着
应用对数据库的需求提升，对传统的数据库服务能力提出了挑战。高并发、高性能、高可用、轻资源、
易维护、易扩展的需求，促进了MySQL的长足发展。
3.3 关于MySQL 8.0
MySQL从5.7版本直接跳跃发布了8.0版本 ，可见这是一个令人兴奋的里程碑版本。MySQL 8版本在功能上做了显著的改进与增强，开发者对MySQL的源代码进行了重构，最突出的一点是多MySQL Optimizer优化器进行了改进。不仅在速度上得到了改善，还为用户带来了更好的性能和更棒的体验。
为什么如此多的厂商要选用MySQL？大概总结的原因主要有以下几点：
开放源代码，使用成本低。性能卓越，服务稳定。软件体积小，使用简单，并且易于维护。历史悠久，社区用户非常活跃，遇到问题可以寻求帮助。许多互联网公司在用，经过了时间的验证。
3.4 Oracle vs MySQL
Oracle 更适合大型跨国企业的使用，因为他们对费用不敏感，但是对性能要求以及安全性有更高的要求。
MySQL 由于其体积小、速度快、总体拥有成本低，可处理上千万条记录的大型数据库，尤其是开放源码这一特点，使得很多互联网公司、中小型网站选择了MySQL作为网站数据库（Facebook，Twitter，YouTube，阿里巴巴/蚂蚁金服，去哪儿，美团外卖，腾讯）。
