Summary:
No matter what database we learn, we should learn the basic concepts. In mongodb, the basic concepts are documents, collections, databases, and we’ll cover them one by one.
The following table will help you understand some concepts in Mongo easier.
data base
Run database C:\Program Files\MongoDB\Server\4.0\bin> first; mongo.exe
show dbs —— Displays a list of all databasesUse -- run"use"Command to connect to a specified database.DB -- Implementation"db" The command can display the current database object or collection.
N...
802.11b/gOr 802.11b/g/n generally supports 13 channels.
Channel is also called channel, frequency band, is a wireless signal (electromagnetic wave) as the transmission carrier of data signal transmission channel. Wireless networks (routers, AP hotspots, and computer wireless network cards) can run on multiple channels. All kinds of wireless network devices should be completed within the coverage of wireless signals.We use different channels to avoid interference between signals. Channel partition of 2.4GHz (=2400MHz) frequency band. There are actually 14 channels (Fourteenth channels are show...
<ScrollViewer x:Name="scrolls" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto" Height="300">
<ScrollViewer.Content>
<StackPanel x:Name="numberedItemsStackPanel" Orientation="Horizontal" ScrollViewer.VerticalScrollBarVisibility="Auto">
…………………………………………
</StackPanel>
</ScrollViewer.Content>
</ScrollViewer>
But I couldn’t scroll through the test after adding it, and it turned out that my StackPanel had set the Height pro...
Method 1:
Menu: “file – Page Setup Manager”
Select “print style”, “print by style” and so on.
Method two:
Print stylesheets select “no”, color printing “press to display”, the highest quality, and the rest default settings.
Print after preview.
WKWebView needs to be reloaded on a particular occasion, but goes directly back to the failed proxy method and reports the following error
Error Domain=WebKitErrorDomain Code=102 “Frame load interrupted”
After looking through the data and testing it, the conclusion is that WebView can reload and succeed when it loads links like “http:\\www.baidu.com”, but loading HTML data is unsuccessful and has not been solved yet.The way to solve the problem remains to be verified.
Summary
Not many people have a thorough understanding of the internal structure and patterns of GPIO (General Purpose Input and Output) processors. Recently, Baidu has searched for a large amount of information on this part, and there is no consensus on many of these issues.This article lists all the questions that IO involves as far as possible, explains clearly the questions that have definite answers, and puts forward the questions where there are still questions for discussion.
Generally speaking, IO’s functional modes can be roughly divided into three categories: input, output and ...
> environment: centos7
ningx version: nginx-1.8.0.tar.gz”
decompression source package to/usr/local > otherwisenginx can not start.
10.cd /usr/local/nginx/sbin
11../nginx Viewnginx start?
After a long time, I finally remembered that I had not finished writing here.
Let’s write a simple piece of the sklearn library today, including data set calls, clustering, contour coefficients, and so on.
Data set function Chinese translation Task type Data scale load_boston BostonHouse price regression 506*13 fetch_california_housing Housing in California regression 20640*9 load_diabetes Diabetes regression 442*10 load_digits Handwriting classification 1797*64 load_breast_cancer Mammary cancer Classification and clustering (357+212)*30 load_iris Iris Classification and clustering (50*...
