2016.05.27

01

整理昨日知识

Vim，SQL语句

02

机器学习中的概念和研究的大致内容

--

03

SQL语句的学习

需求学习法：Django+mysql+web

04

机器学习中的线性代数

线性代数

01

SQL

structured query language:结构化查询语言

02

SVD

--

03

QR分解

--

01

AVG:平均数

SELECT AVG(Realtime) FROM realtime_film;

02

COUNT:计数

SELECT COUNT(Realtime) FROM realtime_film;

03

DISTINCT:唯一值

SELECT DISTINCT Screen_time FROM realtime_film ;

04

MAX:最大值

SELECT MAX(sum_movie)FROM realtime_film;

05

MIN:最小值

SELECT MIN(sum_movie)FROM realtime_film;

06

SUM:全值相加

SELECT MIN(sum_movie)FROM realtime_film;

07

GROUP BY:根据一个或多个列的结果排序

SELECT Customer,OrderDate,SUM(OrderPrice) FROM Orders GROUP BY Customer,OrderDate

08

DELECT:删除语句

DELETE FROM table_name [WHERE Clause]

09

LIKE

SELECT field1, field2,...fieldN table_name1, table_name2... WHERE field1 LIKE condition1 [AND [OR]] filed2 = 'somevalue'

10

ORDER BY:升序或降序排列

SELECT field1, field2,...fieldN table_name1,table_name2...ORDER BY field1, [field2...] [ASC [DESC]]