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Database structure diagram 1. Retrieve data 1.1 select database USE sql5th; 1.2 select a single column select prod_name from Products; +---------------------+ | prod_name | +---------------------+ | Fish bean bag toy | | Bird bean bag toy | | Rabbit bean bag toy | | 8 inch teddy bear | | 12 inch teddy bear | | ...

C/C + + memory distribution Program memory in C/C + + can be divided into kernel space, stack, memory mapping segment, heap, data segment and code segment. Among them, we mainly need to understand: regionfunctionMemory release formStackStore non static local variables, function parameters and return valuesautomaticheapProgram dynamic memo ...

1, Linked list and adjacency list 1 linked list    here, we do not use the commonly used structure plus pointer to realize the linked list, because in this way, each node should be new. The number of linked list nodes in common written test questions is 1e5~1e6 level, and new alone is enough to timeout.   so we use arrays ...

Gateway introduction Background analysis We know that a large-scale system is often divided into many micro services when it is designed. So how can a client call so many microservices? The client can directly send a request to the microservice. Each microservice has a public URL that can be directly mapped to a specific microservice. If ther ...

prefaceWhen using JS to operate DOM nodes, we often use the operation of cloning (or importing) nodes. What methods can achieve the effect of node cloning (or importing)?Today, let's summarize the methods that can achieve the effect of node cloning (or import).node.cloneNode()When it comes to cloning nodes, the first thing we can think of must ...

Before reading this article, it is recommended to read the blogger's article on red black tree, which describes the evolution from binary sort tree → AVL tree → red black tree. Transmission address: Quick understanding of red and black trees HashMap source code analysis + interview questions 1, Hash introduction Core theory ...

Reprinted from: Original link Author: https://gosaintmrc.github.io/ Recently, a meituan interview question appeared on the Internet: "after one thread is OOM, can other threads still run?". I think there are many unreliable answers on the Internet. This question is actually very difficult. The knowledge points involved include ...

1. Wildcard 1.1 effect on documents *: matches any 0 or more characters or strings, including empty strings [root@VM-0-17-centos ~]# rm -f *.sh ?: Match any 1 character [root@VM-0-17-centos ~]# ls ?.* a.out [root@VM-0-17-centos ~]# ls ????.* # Can be used multiple times info.txt test.sh 1.2 action on file / character [abc ...

Experimental environment systemctl stop firewalld 1.journald Service Name: SYSTEMd journal service journalctl Default log storage path: / run/log Experiment 1 usage of journalctl command journalctl -n 3 ## latest 3 entries in log --since "2020-05-01 11:00:00" ## displays the log after 11:00 --until "2020-05-01 11:05:00&quot ...

subjectChief engineer of Redhat and Maintainer of Prometheus open source project Bartłomiej Płotka A Go programming question was asked on Twitter, and more than 80% of the people answered it wrong.The title is as follows. Answer the output of the following program.// named_return.go package main import "fmt" func aaa() (done func(), err error ...