csdnhbgjh的专栏

Rust 10 HashMap 增删查改等常用7种操作：1声明2加增3删除4查找：5修改：更新某key的value等等

use std::fs;use std::fs::OpenOptions;use std::io::prelude::*;fn main() -> std::io::Result<()> { let fieltxt=readtxt(); writetxt(fieltxt); Ok(())}///读取指定文件内容fn readtxt()->String{ let text = fs::read_to_string("D:\\from.t...

Rust 操作 PostgreSQL 数据库 常用操作：一、插入数据-INSERT INTOextern crate postgres;use postgres::{Connection, SslMode};fn main() { let conn = Connection::connect("postgres://postgres@localhost", SslMode::None).unwrap(); conn.execute("INSERT INTO user (userna...