Chapter 7 data filtering
Combine WHERE clause
WHERE vend_id = 1003 AND prod_price <=10;
WHERE vend_id = 1003 OR prod_price <=10;
SELECT prod_price,prod_name, ...
Posted by gckmac on Sun, 23 Feb 2020 13:32:22 +0100
Empty dictionary declaration method
Common declaration method (key: value = 1:1)
Add a new key value pair to the dictionary
Traversal of dictionaries
Common loop traversal and output the value of the corresponding key
Posted by charlie2869 on Sun, 23 Feb 2020 12:32:42 +0100
In daily projects, we often use if to judge, but in multi-level projects, you will find that the code is cumbersome
Now there are four products, namely mobile phones, computers, televisions and game consoles. Of course, the prices of each product are different
To see such a r ...
Posted by Daniel0 on Sun, 23 Feb 2020 11:01:48 +0100
Insights into applets
What is applet
Small program is an application that can be used without downloading and installation. It realizes the dream of "within reach" of the application. Users can scan or search the application to open it. It also embodies the concept of "go ...
Posted by mwd2005 on Sun, 23 Feb 2020 10:29:42 +0100
Dictionary public method
Think about it:
If there is a list
nameList = ['xiaoZhang', 'xiaoWang', 'xiaoLi'];
You need to write the name "xiaoWang" wrong. Modify it by code:
nameList = 'xiaoxiaoWang'
If the order of the list changes, as follows
nameList = ['xiaoW ...
Posted by thepreacher on Sun, 23 Feb 2020 10:01:49 +0100
4, DDL data definition
4.1 create database
4.2 query database
4.3 modify database
4.4 delete database
4.5 create table
4.6 zoning table
4.7 modification table
5, DML data operation
5.1 data import
5.2 data export
5.3 clear data in the table (Truncate)
6.1 basic query ...
Posted by PyroX on Sun, 23 Feb 2020 09:38:46 +0100
Create foreign keys
Common mathematical functions of MySQL
Common string functions of MySQL
Date functions commonly used in MySQL
Other common functions
INSERT [I ...
Posted by juancuca on Sun, 23 Feb 2020 08:59:29 +0100
1, One way circular list
1. One way circular list details
In fact, a unidirectional circular list is a pointer to the head node of the end node. Generally, the end node of the list points to null.
When adding a node, the tail situation is the same as the normal situation, and no special processing i ...
Posted by ghqwerty on Sun, 23 Feb 2020 07:46:35 +0100
Using ffmpeg to split the video file into several ppm pictures
Get path - > unpack - > get video stream information - > decode - > YUV420 to RGB - > store in ppm format.
Step 2. Open audio and video files
Step 3. Get audio and video stream
Posted by iBlizz on Sun, 23 Feb 2020 05:29:45 +0100
Introduction to Alpine Linux
1.Alpine Linux is a lightweight Linux distribution. It is different from the usual Linux distribution (centos, Ubuntu), Alpine uses musl libc and
BusyBox reduces system size and runtime resource consumption.
2.Alpine Linux provides its own package management tool ...
Posted by lanjoky on Sun, 23 Feb 2020 05:29:38 +0100