javaEE(SSM)-4: dynamic SQL
title: javaEE(SSM) learning notes 4: dynamic SQL
Dynamic SQL import
[main function]: splice SQL clauses according to different conditions or different data to achieve similar programming effect in XML files.
[main element (mark)]:
Query criteria: single branch if; Multi branch choose... when... other
Special treatment: where /trim
Up ...
Added by Benjigga on Thu, 10 Mar 2022 18:34:12 +0200
$tools, methods, jQuery properties and CSS
1, What exactly is the $symbol? $is the attribute defined for the window object in jQuery
$and jQuery can be interchanged when used. In fact, it is a function, which comes from the jQuery library
jQuery and $are used as an attribute of window window.jQuery = window.$ = jQuery; ...
Added by traffic on Thu, 10 Mar 2022 17:48:49 +0200
Understand the USB device driver framework in one article
From: https://www.eet-china.com/mp/a55310.html
hello, everybody. Today I'm going to take you to learn about USB device driver.
Kernel version: 4.4.94
1. Linux USB subsystem
Before introducing device-side drivers, let's look at the Linux USB subsystem. The subsystem here is relative to the entire Linux kernel, not a single device. The communic ...
Added by mooler on Thu, 10 Mar 2022 20:14:38 +0200
linux bg and fg commands
linux bg and fg commands
Under linux, if we want a task or program to be executed in the background, we can use &. In fact, linux also provides commands for other task scheduling.
bg: change a command suspended in the background to continue execution; [background background background]fg: transfer the command in the background to the fore ...
Added by radi8 on Thu, 10 Mar 2022 18:38:38 +0200
Linux Environment Configuration
Environment Configuration
Linux
0 .vimrc
#Create a new file in your own directory (~). vimrc
vim ~/.vimrc
#Add a text configuration (as follows...
#Indicates how many spaces a tab shows by default 8
set tabstop=2
#Represents the length of the indentation that falls back when the backspace key is pressed in edit mode
set softtabstop=2
#Re ...
Added by Christian B. on Thu, 10 Mar 2022 20:06:04 +0200
Using invariance to solve concurrency problem
Using invariance to solve concurrency problem
Invariance pattern
We know that concurrency is the most likely cause of thread insecurity. The main reason is that there is data competition. If multiple threads read only and do not modify the same variable, there will be no thread safety problem. This idea is actually very simple, but it is also ...
Added by keevitaja on Thu, 10 Mar 2022 18:48:14 +0200