RKTechGame | Connecting to Database with JDBC

Database se Connection Karne ke Steps

Java me JDBC API use karke database se connect karne ke liye kuch important steps hote hain, jinhe step-by-step yahan samjhaya gaya hai:

1. JDBC Package Import Karna: Java code me JDBC related classes import karna hota hai, jaise java.sql.*.
2. JDBC Driver Load Karna: JDBC driver ko load karna, jo Java ke liye database connection establish karta hai. Example:
   Class.forName("com.mysql.cj.jdbc.Driver"); (MySQL ke liye)
3. Database se Connection establish karna: DriverManager.getConnection() method call karke connection banana. Yahan URL, username, password dena hota hai.
   Example URL: jdbc:mysql://localhost:3306/mydatabase?serverTimezone=UTC
4. SQL Statement create karna: Connection object se createStatement() ya prepareStatement() call karna.
5. Query execute karna: SQL query ko executeQuery() ya executeUpdate() se chalana aur ResultSet me data lena.
6. Resources close karna: Connection, Statement, ResultSet objects ko close karke resources release karna bahut important hota hai.

Simple JDBC Connection Example Code

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class DatabaseConnect {
    public static void main(String[] args) {
        // Database URL, username, password
        String url = "jdbc:mysql://localhost:3306/mydatabase?serverTimezone=UTC";
        String username = "root";
        String password = "yourpassword";

        try {
            // Step 1: Load JDBC driver
            Class.forName("com.mysql.cj.jdbc.Driver");

            // Step 2: Establish connection
            Connection con = DriverManager.getConnection(url, username, password);
            System.out.println("Database connected successfully.");

            // Step 3: Create statement
            Statement stmt = con.createStatement();

            // Step 4: Execute query
            String sql = "SELECT id, name, email FROM users";
            ResultSet rs = stmt.executeQuery(sql);

            // Step 5: Process result
            while (rs.next()) {
                int id = rs.getInt("id");
                String name = rs.getString("name");
                String email = rs.getString("email");
                System.out.println("ID: " + id + ", Name: " + name + ", Email: " + email);
            }

            // Step 6: Close resources
            rs.close();
            stmt.close();
            con.close();
        } catch (ClassNotFoundException e) {
            System.err.println("JDBC Driver not found.");
            e.printStackTrace();
        } catch (SQLException e) {
            System.err.println("Database error:");
            e.printStackTrace();
        }
    }
}

Is example me basic JDBC connection establish karna, query run karna aur result print karna dikhaaya gaya hai.