Java ilovalarida ma'lumotlar bazalari bilan ishlashda JDBC ning asosiy roli va vazifasi nima?

JDBC (Java Database Connectivity) — bu Java'da standart API bo'lib, Java ilovalarining turli ma'lumotlar bazalari bilan o'zaro aloqasini ta'minlaydi. Uning asosiy roli — ma'lumotlar bazasiga ulanish uchun yagona interfeysni taqdim etish, SQL so'rovlarini bajarish va natijalarni qayta ishlash.

JDBC yordamida:

• drayverlar orqali ma'lumotlar bazasiga ulanish mumkin.
• so'rovlar (SELECT, INSERT, UPDATE, DELETE) bajarish.
• So'rov natijalarini qayta ishlash.
• Transaktsiyalarni boshqarish.

JDBC orqali oddiy ulanish va so'rov misoli:

Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "user", "password");
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM users");
while (rs.next()) {
    System.out.println(rs.getString("username"));
}
rs.close();
stmt.close();
conn.close();