MySQL必知必会
花了几天时间，学习了ＭySQL这本书的内容，总体是比较简单易学，对付基本的数据库操作是够用的。主要包含的内容有
- 连接数据库,数据库用户创建，权限设置
- 检索数据
- 排序数据
- 数据过滤，通配符数据过滤
- 正则表达式搜索
- 创建计算字段
- 使用函数处理数据
- 汇总数据
- 分组数据
- 子查询
- 联结表
- 高级联结
- 组合查询
- 全文本搜索
- 插入数据
- 更新和删除数据
- 使用视图
- 存储过程
- 游标
- 触发器
- 事务管理
整理学习时敲的代码如下，仅供记录参考。
USE lk;
show tables;
show columns from products;
select * FROM products;
select distinct vend_id, prod_id from products;
select prod_name from products limit 5;
select prod_name from products limit 5,6;
select prod_name from products limit 5 offset 6;-- 与上相同，表示第５行开始的６行数据
select vend_id from products order by vend_id;
select prod_name from products order by prod_name;
select prod_id,prod_name,prod_price from products order by prod_price desc,prod_name;
select prod_price from products order by prod_price DESC LIMIT 1;
select prod_name,prod_price from products where prod_price >2.5 order by prod_pr;
select prod_name,prod_price from products where prod_name='fuses'; -- 不区分大小写;
select prod_name ,prod_price from products where prod_price between 5 and 30;
select prod_id,prod_name,prod_price from products where prod_price <=10 and vend_id=1001;
select prod_id,prod_name,prod_price from products where vend_id=1002 OR vend_id=1003 order by prod_price DESC;
select prod_id,prod_name,prod_price from products where (vend_id=1002 OR vend_id =1003) AND prod_price>=10 order by prod_price DESC;
select prod_id,prod_name,prod_price from products where vend_id in(1002,1003) and prod_price <=10;
select prod_id,prod_name,prod_price from products where vend_id not in(1002,1003) order by prod_name;
-- 0629
USE lk;
##########################################
#time:0629
#cont:通配符
##########################################
select prod_id,prod_name,prod_price from products where prod_name LIKE 'JET%';
select prod_id,prod_name,prod_price from products where prod_name LIKE '%anvil%';
select prod_id,prod_name,prod_price from products where prod_name LIKE 'anvil%';
select prod_id,prod_name,prod_price from products where prod_name LIKE '%100%';
#正则表达式
select prod_id,prod_name,prod_price from products where prod_name REGEXP '1' ORDER BY PROD_NAME;
select prod_name from products where prod_name REGEXP '.000' order by prod_name;
select prod_name from products where prod_name REGEXP '1000|2000|3000' order by prod_name;
select prod_name from products where prod_name REGEXP '[123] TON' order by prod_name;
select prod_name from products where prod_name REGEXP '\\([0-9] sticks?\\)' order by prod_name;
select prod_name from products where prod_name REGEXP '[[:digit:]]{4}';# 如果只有一个中括号，啥也不返回。
select prod_name from products where prod_name REGEXP '[0-9][0-9][0-9][0-9]';# SAME_name AS THE ONE BEFORE
select prod_name from products where prod_name REGEXP 'stick' order by prod_name;
select prod_name from products where prod_name REGEXP '^[0-9\\.]' order by prod_name;
select 'hello' REGEXP 'l*';#return 1
##10创建计算字段
use vendors;
select * from vendors;
select concat(vend_name,'(',vend_country,')') from vendors order by vend_name;
select concat(rtrim(vend_name),'(',rtrim(vend_country),')') from vendors order by vend_name;
-- 起别名
select concat(rtrim(vend_name),'(',rtrim(vend_country),')') as vend_title from vendors order by vend_name;
select prod_id,quantity,item_price from orderitems where order_num=20005;
select prod_id,
quantity,
item_price,
quantity*item_price as expanded_prices
from orderitems
where order_num=20005;
select now();
select trim(' gooooogle ');
####################################
#time:0629xiawu
#内容：使用函数处理数据
#####################
select vend_name,upper(vend_name) as vend_name_upper from vendors order by vend_name;
select vend_name,length(vend_name) as vend_name_upper from vendors order by vend_name;
select cust_name,cust_contact from customers where soundex(cust_contact) = soundex('Y LIE');
#日期处理函数
select curdate();
SELECT NOW();
select date(NOW());
SELECT cust_id,order_date,order_num from orders where date(order_date)='2005-09-01';
select cust_id,order_date,order_num from orders where date(order_date) between '2005-09-01' and '2005-09-30';
select cust_id,order_date,order_num from orders where year(order_date) and month(order_date) ='9';-- 不加引号也可以.
################################
#１２章 ，聚集函数。
####################
select AVG(prod_price) as avg_price from products;
select AVG(prod_price) as avg_price from products where vend_id=1003;
select count(*) as num_cust from customers;
select count(cust_email) as num_cust from customers;
select max(prod_price) as max_price from products;
select min(prod_price) as min_price from products;
select sum(quantity) as items_ordered from orderitems where order_num=20005;
select quantity ,item_price from orderitems;
select sum(quantity*item_price) as total_price,sum(quantity) as quan from orderitems;-- where order_num=20005;
select AVG(DISTINCT prod_price) as avg_price from products where vend_id=1003;
select AVG(prod_price) as avg_price from products where vend_id=1003;
select count(*) as all_count,
min(prod_price) as min_price,
max(prod_price) as max_price,
avg(prod_price) as avg_price
from products;
#####################################################
#13章，分组数据
#################################################@###
select vend_id,count(*) as num_prods from products group by vend_id;
select cust_id,count(*) as orders from orders group by cust_id having count(*)>=2;
######
#列出具有２个以上，价格大于１０的产品的供应商。
######
select vend_id,count(*) as num_prods
from products
where prod_price >=10
group by vend_id
having count(*)>=2;
select order_num,sum(quantity*item_price) as ordertotal
from orderitems
group by order_num
having sum(quantity*item_price) >=50
order by ordertotal;
##########################################
#time:06３０
#cont:子查询 chapter 14
##########################################
use lk;
select order_num from orderitems where prod_id='TNT2';
select cust_id from orders where order_num in (20005,20007);
-- combaine the two into one
select cust_id from orders where order_num in (select order_num from orderitems where prod_id='TNT2');
select cust_name,cust_contact
from customers
where cust_id in(select cust_id
from orders
where order_num in( select order_num
from orderitems
where prod_id ='TNT2'));
select count(*) as orders from orders where cust_id='10001';
select cust_name,
cust_state,
(select count(*)
from orders
where orders.cust_id=customers.cust_id) as orders
from customers
order by cust_name;
select count(*) as orderss from orders where orders.cust_id=customers.cust_id; -- error,unknown column ´customer.cust_id;´
select count(*) as orderss from orders where orders.cust_id in (select customers.cust_id from customers);
select cust_id from orders;
select distinct customers.cust_id from customers;
##############################################
#chapter 15
#联结
###########################################
select vend_name,prod_name,prod_price from vendors,products where vendors.vend_id=products.vend_id order by vend_name,prod_name;
select vend_name,prod_name,prod_price
from vendors inner join products
on vendors.vend_id=products.vend_id;
#####
#显示编号为２０００５的产品
select prod_name,vend_name,prod_price,quantity
from products,vendors,orderitems
where products.vend_id=vendors.vend_id
and orderitems.prod_id=products.prod_id
and order_num=20005;
#####################################
#chapter 16
#cont:advanced join
#####################################
select cust_name,cust_contact
from customers as c,orders as o,orderitems as oi
where c.cust_id = o.cust_id
and oi.order_num= o.order_num
and prod_id='TNT2';
select prod_id,prod_name
from products
where vend_id=(select vend_id from products where prod_id='DTNTR');
select prod_id,prod_name
from products as p1,products as p2
where p1.vend_id=products.vend_id
and products.prod_id='DTNTR';
select c.*,o.order_num,o.order_date
,oi.prod_id,oi.quantity,oi.item_price
from customers as c,orders as o,orderitems as oi
where c.cust_id=o.cust_id
and oi.order_num=o.order_num
and prod_id='FB';
select customers.cust_id,orders.order_num
from customers inner join orders
on customers.cust_id=orders.cust_id;
select customers.cust_id,orders.order_num
from customers left outer join orders
on customers.cust_id=orders.cust_id;
select customers.cust_name,
customers.cust_id,
count(orders.order_num) as num_ord
from customers inner join orders
on customers.cust_id=orders.cust_id
group by customers.cust_id;
######################################
##chapter 17
##union select
#######################################
use lk;
select prod_id,prod_name,prod_price
from products
where prod_price<=5
order by prod_price DESC;
select prod_id,prod_name,prod_price
from products
where vend_id in(1001,1002);
select prod_id,prod_name,prod_price
from products
where prod_price<=5 union
select prod_id,prod_name,prod_price
from products
where vend_id in(1001,1002);
##################################
#chapter 18
#全文本搜索
###################3#####################
use lk;
select note_text from productnotes
where match(note_text) against('rabbit');
select note_text,
match(note_text) against('rabbit') as rank
from productnotes;
select note_text
from productnotes
where match(note_text) against('anvils');
select note_text
from productnotes
where match(note_text) against('anvils' with query expansion);
select note_text from productnotes
where match(note_text) against('heavy -rope*' in boolean mode);
select note_text from productnotes
where match(note_text) against('+rabbit +bait' in boolean mode);
select note_text from productnotes
where match(note_text) against('rabbit bait' in boolean mode);
select note_text from productnotes
where match(note_text) against('"rabbit bait"' in boolean mode);
select note_text from productnotes
where match(note_text) against('>rabbit in boolean mode); #increase the rank of rabbit ,decrease the rank of bait;
select note_text from productnotes
where match(note_text) against('+safe +( in boolean mode);
#################################################
#chapter 19
#insert
#################################################
#缺点是不安全，必须按照表中定义列的顺序插入数据，如果表的结构发生改变，将会和预计的结果不一致甚至失败。
#有效的方法是插入列名。
insert into customers
values(
NULL,
'Pep E. LaPew',
'100 Main Street',
'Los Angeles',
'CA',
'90046',
'USA',
NULL,
NULL
);
select * from customers;
insert into customers(
CUST_NAME,
cust_address,
cust_city,
cust_state,
cust_zip,
cust_country,
cust_contact,
cust_email)
values(
'Pep E. LaPewG',
'100 Main Street',
'Los Angeles',
'CA',
'90046',
'USA',
NULL,
NULL);
USE lk;
insert into customers(
CUST_NAME,
cust_address,
cust_city,
cust_state,
cust_zip,
cust_country,
cust_contact,
cust_email)
values(
'Pep E. LaPewG',
'100 Main Street',
'Los Angeles',
'CA',
'90046',
'CHN',
NULL,
NULL),(
'M.Martian',
'42 Galaxy Way',
'New Yotk',
'NY',
'11213',
'USA',
NULL,
NULL);
############################################
#CHAPTER 20
#update and delete
#############################################
update customers set cust_email='[email protected]' where cust_id=10005;
delete from customers where cust_id=10006;
create table if not exists orders -- if not exists 创建表时做检查.
(
order_num int NOT NULL auto_increment,
order_state datetime NOT NULL,
cust_id int NOT NULL,
PRIMARY KEY(order_num)
)ENGINE = InnoDB;-- 报警告，提示已经存在表orders。
ALTER TABLE vendors add vend_phone char(20); -- 增加一列
ALTER TABLE vendors drop vend_phone;
ALTER TABLE orderitems add constraint fk_orderitems_orders foreign key(order_num)
references orders(order_num);
DROP TABLE customers;
RENAME TABLE customers2 to customers;
############################################
#chapter 22
#视图
##############################################
select cust_name,cust_contact
from customers,orders,orderitems
where customers.cust_id=orders.cust_id
and orderitems.order_num=orders.order_num
and prod_id='TNT2';
#########################################################
#chapter 22
#view
##########################################################
USE lk;
#####返回已订购任意商品的所有用户的列表
CREATE VIEW productcustomers AS
SELECT cust_name,cust_contact,prod_id
FROM customers,orders,orderitems
WHERE customers.cust_id=orders.cust_id
AND orderitems.order_num =orders.order_num;
SELECT * FROM productcustomers;######返回已订购任意商品的所有用户的列表
SELECT cust_name,cust_contact
FROM productcustomers WHERE prod_id='TNT2';#返回订购了产品ＴＮＴ２的客户。
############################################
#chapter 23
#存储过程
##########################################
DELIMITER //
CREATE PROCEDURE productpricing()
BEGIN
SELECT avg(prod_price) as priceaverage
FROM products;
END //
DELIMITER ;
CALL productpricing(); -- 调用存储过程
DROP PROCEDURE IF EXISTS productpricing;
DELIMITER //
CREATE PROCEDURE productpricing(
OUT pl DECIMAL(8,2),
OUT ph DECIMAL(8,2),
OUT pa DECIMAL(8,2)
)
BEGIN
SELECT Min(prod_price) INTO pl FROM products;
SELECT Max(prod_price) INTO ph FROM products;
SELECT Avg(prod_price) INTO pa FROM products;
END //
DELIMITER ;
CALL productpricing(@pricelow,
@pricehigh,
@priceaverage
);
SELECT @priceaverage;
DELIMITER //
CREATE procedure ordertotal(
IN onumber INT,
OUT ototal DECIMAL(8,2)
)
BEGIN
SELECT Sum(item_price*quantity) INTO ototal FROM orderitems WHERE order_num=onumber;
END //
DELIMITER ;
CALL ordertotal(20005,@total);
SELECT @total;
DELIMITER //
CREATE PROCEDURE ordertotal2(
IN onumber INT,
IN taxable BOOLEAN,
OUT ototal DECIMAL(8,2)
)COMMENT 'Obtain order total,optionally adding tax'
BEGIN
-- Declare variable for total
DECLARE total DECIMAL(8,2);
-- Declare taxrate INDEFUALT 6;
DECLARE taxrate INT DEFAULT 6;
SELECT Sum(item_price*quantity) FROM orderitems WHERE order_num = onumber INTO total;
IF taxable THEN
SELECT total+(total/100*taxrate) INTO total;
END IF;
SELECT total INTO ototal;
END //
DELIMITER ;
CALL ordertotal2(20005,0,@total);
select @total;
CALL ordertotal2(20005,1,@total);
select @total;
SHOW CREATE PROCEDURE ordertotal2;
SHOW PROCEDURE STATUS;
#######################################################
#chapter 24
#使用游标
#######################################################
DELIMITER //
CREATE PROCEDURE processorders2()
BEGIN
DECLARE ordernumbers CURSOR
FOR
SELECT order_num FROM orders;
OPEN ordernumbers;
CLOSE ordernumbers;
END //
DELIMITER ;
-- OPEN ordernumbers;
###############################################
#chapter 25
#触发器# time:0703
##################################################
CREATE TRIGGER newproduct AFTER INSERT ON products
FOR EACH ROW SELECT 'product added';
CREATE TRIGGER neworder2 AFTER INSERT ON orders
FOR EACH ROW SELECT NEW.order_num;
INSERT INTO orders(order_date,cust_id) VALUES(NOW(),10002);
############################################################
#chapter 26
#事务处理
###########################################################
CREATE TABLE ordertotal
(
order_num INT ,
total DECIMAL(8,2)
);
INSERT INTO ordertotal(order_num,total) VALUES(3,6);
SELECT * FROM ordertotal;
START TRANSACTION;
DELETE FROM ordertotal;
SELECT * FROM ordertotal;
ROLLBACK;
SELECT * FROM ordertotal;
-- START TRANSACTION;
-- DELIMITER //
-- DELETE FROM orderitems WHERE order_num=20010;
-- DELETE FROM orders WHERE order_num=20010;
-- COMMIT //
-- DELIMITER ;
use mysql;
select * from user;
CREATE USER ben IDENTIFIED BY 'p@$$wOrd';
select * from user;
rename user ben to bforta;
select * from user;
DROP USER bforta;
SHOW GRANTS FOR bforta;
GRANT SELECT ON crashcourse.* TO bforta;
SHOW GRANTS FOR bforta;
REVOKE SELECT ON crashcourse.* from bforta;
SHOW GRANTS FOR bforta;
SET PASSWORD FOR bforta = password('n3w p@$$wOrd');
SET PASSWORD = Password('nihao p@$$wOrd');
SET PASSWORD =Password('nihao');
use mysql;
select * from user;
use lk;
select @@tx_isolation;