diff --git "a/18 \345\276\220\346\260\270\346\267\263/20230222 \346\225\260\346\215\256\345\272\223\344\275\234\344\270\232.md" "b/18 \345\276\220\346\260\270\346\267\263/20230222 \346\225\260\346\215\256\345\272\223\344\275\234\344\270\232.md" new file mode 100644 index 0000000000000000000000000000000000000000..f7c076344cef694f393078a0474cc08cc2e552c2 --- /dev/null +++ "b/18 \345\276\220\346\260\270\346\267\263/20230222 \346\225\260\346\215\256\345\272\223\344\275\234\344\270\232.md" @@ -0,0 +1,111 @@ +```mysql + + + +CREATE DATABASE test01_company CHARSET utf8; +USE test01_company; +CREATE TABLE offices( + officeCode INT, + city VARCHAR(30), + address VARCHAR(50), + country VARCHAR(50), + postalCode VARCHAR(25) +); +CREATE TABLE employees( + empNum INT(11), + lastName VARCHAR(50), + firstName VARCHAR(50), + mobile VARCHAR(25), + code INT, + jobTitle VARCHAR(50), + birth date, + Note VARCHAR(255), + Sex VARCHAR(5) +); +ALTER TABLE employees MODIFY mobile VARCHAR(25) AFTER code; +ALTER TABLE employees CHANGE birth birthday DATE; +ALTER TABLE employees MODIFY sex CHAR(1); +ALTER TABLE employees DROP note; +ALTER TABLE employees ADD favoriate_activity VARCHAR(100); +ALTER TABLE employees RENAME employees_info; + + + +CREATE DATABASE test02db CHARSET utf8; +USE test02db; +CREATE TABLE pet( + name VARCHAR(20) , + owner VARCHAR(20) , + species VARCHAR(20), + sex CHAR(1) , + birth year, + death year +); +INSERT INTO pet VALUES ('Fluffy','harold','Cat','f','2003','2010'), ('Claws','gwen','Cat','m','2004',NULL), ('Butty',NULL,'Dog','f','2009',NULL), ('Fang','benny','Dog','m','2000',NULL), ('bowser','diane','Dog','m','2003','2009'), ('Chirpy',NULL,'Bird','f','2008',NULL); +ALTER TABLE pet ADD owner_birth DATE; +UPDATE pet SET owner='kevin' WHERE NAME='Claws'; +UPDATE pet SET owner='duck' WHERE species='dog' AND OWNER IS null; +SELECT*FROM pet WHERE OWNER IS null; +SELECT name,owner, death FROM pet WHERE species='cat' AND death IS NOT NULL; +DELETE FROM pet WHERE death is not null and species = 'Dog'; + + + + +CREATE DATABASE test03_company CHARSET utf8; +use test03_company; +create table department( + depid int primary KEY, + depname char(10) not null , + deinfo varchar(200) +); +CREATE TABLE employee ( +empid int PRIMARY KEY, +name VARCHAR(50), +sex enum('男','女') not null DEFAULT '男', +title VARCHAR(10), +birthday DATE, +depid int,FOREIGN key employee(depid) REFERENCES department(depid) on update cascade on delete set null +); +CREATE TABLE salary ( +empid INT PRIMARY KEY, +basesalary int, +titlesalary int , +deduction INT +); +ALTER TABLE salary ADD FOREIGN KEY(empid) REFERENCES employee(empid) ON UPDATE CASCADE ON DELETE CASCADE; +INSERT INTO department VALUES(111,'生产部',NULL),(222,'销售部',NULL),(333,'人事部','人力资源管理'); +INSERT INTO employee VALUES(1001,'张三','男','高级工程师','1975-1-1',111),(1002,'李四','女','助工','1985-1-1',111),(1003,'王五','男','工程师','1978-11-11',222),(1004,'张六','男','工程师','1999-1-1',222); +INSERT INTO salary VALUES( 1001 , 2200 , 1100 , 200 ),( 1002 ,1200,200,NULL),(1003,2900,700,200),(1004,1950,700,150); + + + +CREATE DATABASE test04_school CHARSET utf8; +use test04_school; +CREATE TABLE Department( +DepNo int(10) PRIMARY KEY not null UNIQUE key, +DepName VARCHAR(20) NOT null, +DepNote Varchar(50) +); +CREATE TABLE Teacher( +Number int PRIMARY KEY NOT null unique key, +Name VARCHAR(30) not null, +sex VARCHAR(4), +birth date, +DepNo int, FOREIGN KEY teacher(depno) REFERENCES Department(DepNo), +Salary FLOAT, +Address VARCHAR(100) +); +INSERT INTO Department VALUES (601,'软件设计系','软件技术等专业'),(602,'网络技术系','多媒体技术等专业'),(603,'艺术设计系','广告艺术设计等专业'),(604,'管理工程系','连锁经营管理等专业'); +INSERT INTO Teacher VALUES(2001,'Tom','女','1970-01-10',602,4500,'四川省绵阳市'),(2002,'Lucy','男','1983-12-18',601,2500,'北京市昌平区'),(2003,'Mike','男','1990-06-01',604,1500,'重庆市渝中区'),(2004,'James','女','1980-10-20',602,3500,'四川省成都市'),(2005,'Jack','男','1975-05-30',603,1200,'重庆市南岸区'); +SELECT*FROM teacher; +``` + +查询全部要用 select*from 库名 + +查询部分要用 select 需要查询的信息 from 库名 + +如果查询要两个条件 可以在后面加 and 若值为空 可以填 信息 is null + +主键 primary key 外键 foreign key 库名（表名）reference 其他库名（对方主键）、 + diff --git "a/18 \345\276\220\346\260\270\346\267\263/20230223 \346\225\260\346\215\256\345\272\223\344\275\234\344\270\232.md" "b/18 \345\276\220\346\260\270\346\267\263/20230223 \346\225\260\346\215\256\345\272\223\344\275\234\344\270\232.md" new file mode 100644 index 0000000000000000000000000000000000000000..0d860fa3063fe21146d570818afdd4b7fa481611 --- /dev/null +++ "b/18 \345\276\220\346\260\270\346\267\263/20230223 \346\225\260\346\215\256\345\272\223\344\275\234\344\270\232.md" @@ -0,0 +1,60 @@ +```sql +CREATE DATABASE goodbye CHARSET utf8; +USE goodbye; +CREATE TABLE employee( + id INT, + `name` VARCHAR(20), + sex VARCHAR(20), + tel VARCHAR(20), + addr VARCHAR(50), + salary FLOAT +); + +#添加信息 +INSERT INTO employee(id,`name`,sex,tel,addr,salary)VALUES +(10001,'张一一','男','13456789000','广东韶关',10010.58), +(10002,'刘小红','女','13454319000','广东江门',12010.21), +(10003,'李四','男','0751-1234567','广东佛山',10040.11), +(10004,'刘小强','男','0755-5555555','广东深圳',15010.23), +(10005,'王艳','男',NULL,'广东广州',14050.16); +SELECT*FROM employee where salary>12000 and salary<13000; +SELECT NAME FROM employee WHERE NAME LIKE '刘%'; +UPDATE employee SET addr='广东韶关' WHERE name='李四'; +SELECT NAME FROM employee WHERE NAME LIKE '%小%'; +SELECT*FROM employee WHERE salary>11000 AND sex='男'; +SELECT*FROM employee where tel is null; +SELECT*FROM employee WHERE (salary>12000 AND sex='男' ) OR (addr='广州' AND ADDr='广东深圳'); +SELECT name ,salary FROM employee; +``` + + + +```sql +CREATE DATABASE sever CHARSET utf8; +use sever; +CREATE TABLE `countries_info`( + `name` VARCHAR(100), + `continent` VARCHAR(100), + `area` INT, + population INT, + gdp BIGINT +); + +INSERT INTO countries_info VALUES +('Afghanistan','Asia',652230,25500100,20343000000), +('Albania','Europe',28748,2831741,12960000000), +('Algeria','Africa',2381741,37100000,188681000000), +('Andorra','Europe',468,78115,3712000000), +('Angola','Africa',1246700,20609294,100990000000); +SELECT name, area ,population FROM countries_info WHERE area>=3000000 or population>=25000000; +SELECT*FROM countries_info WHERE continent='asia'; +SELECT*FROM countries_info WHERE area<=10000 AND population<=100000; +SELECT*FROM countries_info WHERE NAME LIKE '%o%'; +SELECT*FROM countries_info WHERE gdp>10000000000; +SELECT name 国家,population 人口,gdp gdp值,gdp/population 人均gdp值 FROM countries_info ; +SELECt * ,gdp/population 人均gdp值 from countries_info WHERE gdp/population<1000; +SELECT name 国家名,area 面积,population 人口,area/population 人均国土面积值 FROM countries_info; +``` + + +