Insert a record into the database. If the primary key value (UNIQUE KEY) of the data already exists in the table, perform the following UPDATE operation. Otherwise, perform the previous INSERT oper
Month: October 2021
How to convert a C string into a RUST string and return via FFI?
I am trying to get the C string returned by the C library and convert it to a Rust string through FFI.
mylib.c
const char* hello(){
return “Hello World!”;
} main.rs
#![feature(li
C # Online! Third article: Even C # is no exception! This is a newcomer to do things!!
C# Online! Chapter 3: Even C# is no exception! This is something newbies do!!
Friends who have played online games must know that the game At the beginning, novices will have something to do.
C # with Unity Data Storage
Use Json to store data
1. Create a Json file, create a txt file directly, and change the suffix to xx.json
2. The data format of the Json file , The square brackets indicate the list, t
What is the meaning in mysql?
What does group by mean in mysql syntax? After searching for a long time in Baidu, I finally found an article with a better explanation (not a blog post, but Baidu knows it, so depressed, so many n
MySQL index failure scene
For example: a USER table has field attributes name, age, where name is an index
The following are some examples of index failures
1. select * from USER where name=’xzz’ or age=16;
<
C # interface
1 //Public interface: “Animals”
2 public interface IAnimal
3 {
4 void Behavior(); //behavior methods, describing the characteristics of various animals
5 }
6
7 //Class: Dog
8 publi
Calculate the number of characters in the string in c
How to count the number of “_” in a string like “bla_bla_blabla_bla”? #include
std::string s = “a_b_c “;
size_t n = std::count(s.begin(), s.end(),’_’);
How to calculate like ” The number
[Vs] [C #] Add log4net for the project ~
Summary: [VS] [C#] Let’s join log4net for the project~
I just came into contact with the useful log4net recently,
I am writing Window Service
Of course, it is inevitable to join i
C # variable
Data type 1), integer type: int can only store integers, not decimals.
2). Decimal type: double can store both integers and decimals. The number of digits after the decimal point is 15~16.
3), mo