# 創(chuàng)建部門(mén)表
 CREATE TABLE dept(
  id INT PRIMARY KEY AUTO_INCREMENT,
  NAME VARCHAR(20)
 );
 INSERT INTO dept (NAME) VALUES ('開(kāi)發(fā)部'),('市場(chǎng)部'),('財(cái)務(wù)部');
 # 創(chuàng)建員工表
 CREATE TABLE emp (
  id INT PRIMARY KEY AUTO_INCREMENT,
  NAME VARCHAR(10),
  gender CHAR(1), -- 性別
  salary DOUBLE, -- 工資
  join_date DATE, -- 入職日期
  dept_id INT,
  FOREIGN KEY (dept_id) REFERENCES dept(id) -- 外鍵，關(guān)聯(lián)部門(mén)表(部門(mén)表的主鍵)
 );
 INSERT INTO emp(NAME,gender,salary,join_date,dept_id) VALUES('孫悟空','男',7200,'2013-02-24',1);
 INSERT INTO emp(NAME,gender,salary,join_date,dept_id) VALUES('豬八戒','男',3600,'2010-12-02',2);
 INSERT INTO emp(NAME,gender,salary,join_date,dept_id) VALUES('唐僧','男',9000,'2008-08-08',2);
 INSERT INTO emp(NAME,gender,salary,join_date,dept_id) VALUES('白骨精','女',5000,'2015-10-07',3);
 INSERT INTO emp(NAME,gender,salary,join_date,dept_id) VALUES('蜘蛛精','女',4500,'2011-03-14',1);

-- 查詢(xún)所有員工信息和對(duì)應(yīng)的部門(mén)信息
SELECT * FROM emp,dept WHERE emp.`dept_id` = dept.`id`;
-- 查詢(xún)員工表的名稱(chēng)，性別。部門(mén)表的名稱(chēng)
SELECT emp.name,emp.gender,dept.name FROM emp,dept WHERE emp.`dept_id` = dept.`id`;
   
SELECT 
t1.name, -- 員工表的姓名
t1.gender,-- 員工表的性別
t2.name -- 部門(mén)表的名稱(chēng)
FROM
 emp t1,
 dept t2
WHERE 
t1.`dept_id` = t2.`id`;

* SELECT * FROM emp INNER JOIN dept ON emp.`dept_id` = dept.`id`; 
* SELECT * FROM emp JOIN dept ON emp.`dept_id` = dept.`id`; 

-- 查詢(xún)所有員工信息，如果員工有部門(mén)，則查詢(xún)部門(mén)名稱(chēng)，沒(méi)有部門(mén)，則不顯示部門(mén)名稱(chēng)
SELECT  t1.*,t2.`name` FROM emp t1 LEFT JOIN dept t2 ON t1.`dept_id` = t2.`id`;

SELECT  * FROM dept t2 RIGHT JOIN emp t1 ON t1.`dept_id` = t2.`id`;

SELECT id FROM dept WHERE NAME = '財(cái)務(wù)部' OR NAME = '市場(chǎng)部';
SELECT * FROM emp WHERE dept_id = 3 OR dept_id = 2;
-- 子查詢(xún)
SELECT * FROM emp WHERE dept_id IN (SELECT id FROM dept WHERE NAME = '財(cái)務(wù)部' OR NAME = '市場(chǎng)部');

SELECT * FROM dept t1 ,(SELECT * FROM emp WHERE emp.`join_date` > '2011-11-11') t2
WHERE t1.id = t2.dept_id;   

SELECT * FROM emp t1,dept t2 WHERE t1.`dept_id` = t2.`id` AND t1.`join_date` >  '2011-11-11'

   -- 部門(mén)表
   CREATE TABLE dept (
     id INT PRIMARY KEY PRIMARY KEY, -- 部門(mén)id
     dname VARCHAR(50), -- 部門(mén)名稱(chēng)
     loc VARCHAR(50) -- 部門(mén)所在地
   );
   
   -- 添加4個(gè)部門(mén)
   INSERT INTO dept(id,dname,loc) VALUES 
   (10,'教研部','北京'),
   (20,'學(xué)工部','上海'),
   (30,'銷(xiāo)售部','廣州'),
   (40,'財(cái)務(wù)部','深圳');

   -- 職務(wù)表，職務(wù)名稱(chēng)，職務(wù)描述
   CREATE TABLE job (
     id INT PRIMARY KEY,
     jname VARCHAR(20),
     description VARCHAR(50)
   );
   
   -- 添加4個(gè)職務(wù)
   INSERT INTO job (id, jname, description) VALUES
   (1, '董事長(zhǎng)', '管理整個(gè)公司，接單'),
   (2, '經(jīng)理', '管理部門(mén)員工'),
   (3, '銷(xiāo)售員', '向客人推銷(xiāo)產(chǎn)品'),
   (4, '文員', '使用辦公軟件');

   -- 員工表
   CREATE TABLE emp (
     id INT PRIMARY KEY, -- 員工id
     ename VARCHAR(50), -- 員工姓名
     job_id INT, -- 職務(wù)id
     mgr INT , -- 上級(jí)領(lǐng)導(dǎo)
     joindate DATE, -- 入職日期
     salary DECIMAL(7,2), -- 工資
     bonus DECIMAL(7,2), -- 獎(jiǎng)金
     dept_id INT, -- 所在部門(mén)編號(hào)
     CONSTRAINT emp_jobid_ref_job_id_fk FOREIGN KEY (job_id) REFERENCES job (id),
     CONSTRAINT emp_deptid_ref_dept_id_fk FOREIGN KEY (dept_id) REFERENCES dept (id)
   );
   
   -- 添加員工
   INSERT INTO emp(id,ename,job_id,mgr,joindate,salary,bonus,dept_id) VALUES 
   (1001,'孫悟空',4,1004,'2000-12-17','8000.00',NULL,20),
   (1002,'盧俊義',3,1006,'2001-02-20','16000.00','3000.00',30),
   (1003,'林沖',3,1006,'2001-02-22','12500.00','5000.00',30),
   (1004,'唐僧',2,1009,'2001-04-02','29750.00',NULL,20),
   (1005,'李逵',4,1006,'2001-09-28','12500.00','14000.00',30),
   (1006,'宋江',2,1009,'2001-05-01','28500.00',NULL,30),
   (1007,'劉備',2,1009,'2001-09-01','24500.00',NULL,10),
   (1008,'豬八戒',4,1004,'2007-04-19','30000.00',NULL,20),
   (1009,'羅貫中',1,NULL,'2001-11-17','50000.00',NULL,10),
   (1010,'吳用',3,1006,'2001-09-08','15000.00','0.00',30),
   (1011,'沙僧',4,1004,'2007-05-23','11000.00',NULL,20),
   (1012,'李逵',4,1006,'2001-12-03','9500.00',NULL,30),
   (1013,'小白龍',4,1004,'2001-12-03','30000.00',NULL,20),
   (1014,'關(guān)羽',4,1007,'2002-01-23','13000.00',NULL,10);

   -- 工資等級(jí)表
   CREATE TABLE salarygrade (
     grade INT PRIMARY KEY,   -- 級(jí)別
     losalary INT,  -- 最低工資
     hisalary INT -- 最高工資
   );
   
   -- 添加5個(gè)工資等級(jí)
   INSERT INTO salarygrade(grade,losalary,hisalary) VALUES 
   (1,7000,12000),
   (2,12010,14000),
   (3,14010,20000),
   (4,20010,30000),
   (5,30010,99990);

    SELECT 
    t1.`id`, -- 員工編號(hào)
    t1.`ename`, -- 員工姓名
    t1.`salary`,-- 工資
    t2.`jname`, -- 職務(wù)名稱(chēng)
    t2.`description` -- 職務(wù)描述
   FROM 
    emp t1, job t2
   WHERE 
    t1.`job_id` = t2.`id`;

  SELECT 
    t1.`id`, -- 員工編號(hào)
    t1.`ename`, -- 員工姓名
    t1.`salary`,-- 工資
    t2.`jname`, -- 職務(wù)名稱(chēng)
    t2.`description`, -- 職務(wù)描述
    t3.`dname`, -- 部門(mén)名稱(chēng)
    t3.`loc` -- 部門(mén)位置
   FROM 
    emp t1, job t2,dept t3
   WHERE 
    t1.`job_id` = t2.`id` AND t1.`dept_id` = t3.`id`;  

  SELECT 
    t1.ename ,
    t1.`salary`,
    t2.*
   FROM emp t1, salarygrade t2
   WHERE t1.`salary` BETWEEN t2.`losalary` AND t2.`hisalary`;

     SELECT 
    t1.`ename`,
    t1.`salary`,
    t2.`jname`,
    t2.`description`,
    t3.`dname`,
    t3.`loc`,
    t4.`grade`
   FROM 
    emp t1,job t2,dept t3,salarygrade t4
   WHERE 
    t1.`job_id` = t2.`id` 
    AND t1.`dept_id` = t3.`id`
    AND t1.`salary` BETWEEN t4.`losalary` AND t4.`hisalary`;

   SELECT 
    t1.`id`,t1.`dname`,t1.`loc` , t2.total
   FROM 
    dept t1,
    (SELECT
     dept_id,COUNT(id) total
    FROM 
     emp
    GROUP BY dept_id) t2
   WHERE t1.`id` = t2.dept_id;

   select
    t1.ename,
    t1.mgr,
    t2.`id`,
    t2.ename
   from emp t1, emp t2
   where t1.mgr = t2.`id`;

   SELECT 
    t1.ename,
    t1.mgr,
    t2.`id`,
    t2.`ename`
   FROM emp t1
   LEFT JOIN emp t2
   ON t1.`mgr` = t2.`id`;

  CREATE TABLE account (
   id INT PRIMARY KEY AUTO_INCREMENT,
   NAME VARCHAR(10),
   balance DOUBLE
  );
  -- 添加數(shù)據(jù)
  INSERT INTO account (NAME, balance) VALUES ('zhangsan', 1000), ('lisi', 1000);
​

  SELECT * FROM account;
  UPDATE account SET balance = 1000;
  -- 張三給李四轉(zhuǎn)賬 500 元
  
  -- 0. 開(kāi)啟事務(wù)
  START TRANSACTION;
  -- 1. 張三賬戶(hù) -500
  
  UPDATE account SET balance = balance - 500 WHERE NAME = 'zhangsan';
  -- 2. 李四賬戶(hù) +500
  -- 出錯(cuò)了...
  UPDATE account SET balance = balance + 500 WHERE NAME = 'lisi';
  
  -- 發(fā)現(xiàn)執(zhí)行沒(méi)有問(wèn)題，提交事務(wù)
  COMMIT;
  
  -- 發(fā)現(xiàn)出問(wèn)題了，回滾事務(wù)
  ROLLBACK;

set global transaction isolation level read uncommitted;
start transaction;
-- 轉(zhuǎn)賬操作
update account set balance = balance - 500 where id = 1;
update account set balance = balance + 500 where id = 2;

UPDATE USER SET PASSWORD = PASSWORD('新密碼') WHERE USER = '用戶(hù)名';
UPDATE USER SET PASSWORD = PASSWORD('abc') WHERE USER = 'lisi';
SET PASSWORD FOR '用戶(hù)名'@'主機(jī)名' = PASSWORD('新密碼');
SET PASSWORD FOR 'root'@'localhost' = PASSWORD('123');

SHOW GRANTS FOR '用戶(hù)名'@'主機(jī)名';
SHOW GRANTS FOR 'lisi'@'%';