Advanced java concept

==================================================== JDBC – SERVLET – JSP NOTES 🔷 1. JDBC – ResultSet Interface • ResultSet is an interface from java.sql package. • Represents data returned by SQL SELECT query. • Used for: - Retrieving data - Navigating rows - Manipulating data 🔹 Creating ResultSet Using Statement: Statement stm = con.createStatement(); ResultSet rs = stm.executeQuery("SELECT * FROM emp"); Using PreparedStatement: PreparedStatement ps = con.prepareStatement("SELECT * FROM emp"); ResultSet rs = ps.executeQuery(); 🔷 2. Types of ResultSet 1) TYPE_FORWARD_ONLY (Default) • Move only forward • Cannot move backward • Cannot jump to specific row 2) TYPE_SCROLL_INSENSITIVE • Move forward & backward • Jump to any row • Does NOT reflect DB changes 3) TYPE_SCROLL_SENSITIVE • Move forward & backward • Reflects DB changes 🔷 3. Concurrency Mode ResultSet.CONCUR_READ_ONLY • Cannot update data ResultSet.CONCUR_UPDATABLE • Can update data 🔷 4. Important ResultSet Methods next() → Move t