Mobile versionAllgemeines Handbuch < /h2>
Projektverzeichnis im Terminal erstellen < /h3>
Code: Select all
mkdir "Project name"
cd "Project name"
mkdir backend
mkdir "subdirectory2"
mkdir "subdirectory3"
< /code>
[h4] Nützliche Webseiten < /h4>
[*] Stackoverflow < /li>
w3schools < /li>
Bootstrap < /li> < /> < />
VSC -Ausstreckungen: < /h4>
vscs: < /h4>
vscs: < /h4>
vscs: < /h4>
vscs: < /h4>
vscs: < /h4>
vscs: < /h4>
vscs: < /h4>
vsc. /> Easyzoom < /li>
Live -Server < /li>
Thunder Client < /li>
automatisch umbenennen. C: \ xampp \ mysql \ backup [*] Navigieren Sie zu: c: \ xampp \ mysql \ data
[*] c/> c/> c/> c/> c/> cll + a [*] Einfügen
Desktop
Ziel Finish-Zeit: ~ 1H 25min
Klassen und Konstruktoren
class Person
{
public int id { get; set; }
public double average { get; set; }
public string name { get; set; }
public DateTime date { get; set; }
public Person(int id, double average, string name, DateTime date)
{
this.id = id;
this.average = average;
this.name = name;
this.date = date;
}
}
< /code>
Textmanipulation < /h3>
Code: Select all
Replace(',','-'); // 2019-2-12
Trim('-'); // 2019212
Split(','); // {apple, banana, orange}
Contains("YES") // returns true
char[] nameArray = {'A', 'l', 'i', 'c', 'e'};
string name = new string(nameArray);
Math.Round(number, 2)); // 5.43529 -> 5.44 (Honorable mention: Floor(), Ceiling())
< /code>
Lesen einer Datei < /h3>
using System.IO;
< /code>
List peopleList = new List();
using (StreamReader sr = new StreamReader("filename.txt"))
{
while (!sr.EndOfStream)
{
string line = sr.ReadLine();
string[] data = line.Split(';');
int id = int.Parse(data[0]);
data[1] = data[1].Replace(',', '.');
double atlag = double.Parse(data[1]);
string name = data[2];
DateTime date = Convert.ToDateTime(data[3]);
Person person = new Person(id, average, name, date);
peopleList.Add(person);
}
}
< /code>
Erstellen einer Datei < /h3>
using (StreamWriter sw = File.CreateText("filename.txt"))
{
sw.WriteLine("...");
}
< /code>
linq Beispiele < /h3>
using System.Linq;
< /code>
foreach (var group in groupedByYear)
{
Console.WriteLine($"Year: {group.Year}");
foreach (var person in group.People)
{
Console.WriteLine($"- {person.Name}");
}
}
< /code>
1. Aggregation (Anzahl, Summe, Durchschnitt, max, min) < /h4>
Statistik berechnen.int count = people.Count(); // Total people
int over30Count = people.Count(p => p.Age > 30); // People over 30
double totalSalary = people.Sum(p => p.Salary); // Total salary
double avgSalary = people.Average(p => p.Salary); // Average salary
int maxAge = people.Max(p => p.Age); // Oldest age
< /code>
2. Filterung (wo) < /h4>
Wählen Sie Personen, die älter als 25 Jahre alt sind.var olderThan25 = people.Where(p => p.Age > 25);
< /code>
3. Sortieren (orderby, thenby) < /h4>
Sortieren Sie Personen nach Alter, dann nach Namen.var sortedPeople = people.OrderBy(p => p.Age).ThenBy(p => p.Name);
< /code>
4. Auswählen spezifischer Felder (auswählen) < /h4>
eine Liste von Namen und Gehältern abrufen.var namesAndSalaries = people.Select(p => new { p.Name, p.Salary });
< /code>
5. Gruppierung (GroupBy) < /h4>
Gruppenpersonen nach Alter.var groupedByAge = people.GroupBy(p => p.Age).Select(g => new { Age = g.Key, People = g });
< /code>
6. Erstens zuletzt einzeln < /h4>
bestimmte Elemente abrufen.Person firstPerson = people.First(); // First person
Person lastPerson = people.Last(); // Last person
Person singlePerson = people.Single(p => p.Id == 1); // Person with Id 1
< /code>
7. Alle und alle < /h4>
Überprüfen Sie die Bedingungen.bool hasYoung = people.Any(p => p.Age < 25); // True if any person is under 25
bool allHighEarners = people.All(p => p.Salary > 40000); // True if all earn > 40k
< /code>
Tipps für effektives linq < /h4>
[b] Leistung < /strong>: [url=viewtopic.php?t=15143]Vermeiden[/url] Sie mehrere Aufzählungen; Ergebnisse mit .tolist () installiert die erforderlichen Pakete im Backend-Ordner und erstellt app.js/index.js-Datei mit grundlegendem Inhalt [/h4]
Code: Select all
cd backend
npm install express mysql2 cors
npm pkg set type=module
cd backend
echo "import express from 'express';" > app.js
echo "import cors from 'cors';" >> app.js
echo "import mysql from 'mysql2';" >> app.js
echo "" >> app.js
echo "const app = express();" >> app.js
echo "app.use(cors());" >> app.js
echo "app.use(express.json());" >> app.js
echo "" >> app.js
echo "const db = mysql.createConnection({" >> app.js
echo " host: 'localhost'," >> app.js
echo " user: 'root'," >> app.js
echo " password: ''," >> app.js
echo " database: '', // Database name goes here" >> app.js
echo " port: 3306" >> app.js
echo "});" >> app.js
echo "" >> app.js
echo "// endpoints" >> app.js
echo "" >> app.js
echo "app.listen(3000, () => {" >> app.js
echo " console.log('Server is running on http://localhost:3000');" >> app.js
echo "});" >> app.js
< /code>
Endpunkte < /h3>
import express from "express";
import mysql from "mysql2";
import cors from "cors";
const app = express();
const port = 3000;
app.use(express.json());
app.use(cors());
const db = mysql.createConnection({
host: "localhost",
user: "root",
password: "",
database: "namedays",
});
// API endpoint to get nameday by date
app.get("/api/nameday/", (req, res) => {
// Extract "date" from query parameter
const date = req.query.date; // KEY
// Check if date is specified
if (!date) {
return res.status(400).json({ error: "Date parameter is required" });
}
// get the month and day
const month = date.split("-")[0];
const monthName = convertMonthNumberToName(month);
const day = date.split("-")[1];
const sql = SELECT name1, name2 FROM nameday WHERE month = ${month} AND day = ${day};
db.query(sql, (err, result) => {
if (err) {
console.log("Server error");
}
if (result.length === 0) {
console.log("No nameday found");
}
const nameday = result[0];
// Send response with formatted date and nameday data
res.json({ // KEY
date: `${monthName} ${day}.`,
name1: nameday.name1,
name2: nameday.name2,
});
});
});
// Function to convert month number to month name
function convertMonthNumberToName(monthNumber) {
switch (monthNumber) {
case "1":
return "January";
case "2":
return "February";
...
}
}
// Delete data by ID
app.delete("/api/nameday/:id", async (req, res)=>{
const id = req.params.id; // Extracts the ID from the URL parameter, e.g., /api/nameday/123
const sql = "DELETE FROM nameday WHERE id = ?";
const [result] = await database.execute(sql, [id]);
res.status(200).json(result);
})
app.listen(port, () => {
console.log(`Server is running on port ${port}`);
});
Ziel-Endzeit: ~ 1H 30min [/b]
stootstrap import
Code: Select all
< /code>
Anzeige und Senden von Karten dynamisch mit Bootstrap < /h3>
Select Date:
Get Nameday
// Place for the cards
// Handle form submission
document.getElementById('dateForm').addEventListener('submit', async (e) => {
e.preventDefault();
const date = document.getElementById('dateInput').value;
if (!date) return;
// Clear previous cards
const cardContainer = document.getElementById('namedayCards');
cardContainer.innerHTML = '';
// Fetch data from API
try {
const response = await fetch(`http://localhost:3000/api/nameday/?date=${date}`);
if (!response.ok) {
throw new Error('Failed to fetch nameday data');
}
const data = await response.json();
// Check for error response
if (data.error) {
cardContainer.innerHTML = `${data.error}`;
return;
}
// Create Bootstrap cards for each name
const names = [data.name1, data.name2];
names.forEach(name => {
const card = document.createElement('div');
card.className = 'col';
card.innerHTML = `
${name}
Nameday on ${data.date}
`;
cardContainer.appendChild(card);
});
} catch (error) {
console.error('Error:', error);
cardContainer.innerHTML = `Error fetching data`;
}
});