Python Operation Memcache/redis/rabbitmq

Database operations:
-Database
-table
A. single table

B. One-to-many
user type:
1 Super User
2 Normal user
32 user
User:
Way 3 (set number, constraint = foreign key (table, column )
Liu Hao 6
He Lei 3
He Lei 3


C. Many-to-many
hosts: Host name ....
1 c1.com
2 c1.com
3 c1.com
4 c1.com

User table: User name ....
1 yan Breeding
2 lo Rao
3 Muddy
4 use three

Install B:
User host Time
4 1,
4 2,
4 1,
4 2,
3 2,


Blind Date:
1 Strict breeding
2 Lu Rao
3 Muddy
4 use three


Record:
Unisex
4 3 ()
4 3
4 2
1 3

+ Union UNIQUE constraint: (male and female) br>-Data Manipulation
Add
INSERT into TB (name,age) VALUES (' root ', +)
Delete
Delete from TB where ID > 1
Change
Update TB Set age=73 where name= ' Alex '
Check
Select * from TB;
SELECT * from TB where ID >
Select nid,username,pwd from TB where ID >

-pymysql
1. Execute (' Sele CT * from terabytes where name=%s ', ' root ')
2. Execute ("SELECT * from TB"); Fetchone ...
3. [(1,root,19), (2,root,19),]
[{},{},]
4. Lastrowid get the self-increment ID value

1. mysql Supplement
GROUP BY
-Aggregate sum (SID), Max (SID), Min (SID), COUNT (SID) for the column
-Aggregation condition filtering, having count (SID) > 7

Even table operation
-INNER JOIN: null not present
-LEFT JOIN: How many shows how many, even the table has no corresponding entry: null
-Right Join

Ps:
Fk:
-Save Save
-Slow query
Pros: Easy for programmers

No FK:
-Storage does not save
-Fast Query
Advantages: Fast Query
Cons: Programmers maintain data

Django: A magical double-down route

Exercises:
Http://www.cnblogs.com/wupeiqi/articles/5729934.html
Http://www.cnblogs.com/wupeiqi/articles/5748496.html

2. Memcached
Service side:
Software on a remote server, manipulating data in memory
Dictionary: {
K: "Asdfasdf",
K: "Asdfasdf",
}
Client
Connection:
Python-memcached
Pylibmc

3. Redis

{
K1: "Asdfasdf", String strings
K2:[1,2,1,2],list List
k3:{' K1 ': 1, ' K2 ': 2},hash dictionary
k4:{1,2,4,5,1,}, collection
k5:{(1,60), (2,70), (3,6)}, ordered collection
}


1. Connect
2. Connection pooling
Pool = Redis. ConnectionPool (host= ' 10.211.55.4 ', port=6379, max_connections=10)
conn = Redis. Redis (Connection_pool=pool)
3. Support Transactions
4. Publishing and subscribing

4. RabbitMQ

Exchange ==>


Rpc

Python Operation Memcache/redis/rabbitmq