? JDBC Update Operation

? Quick Overview

The JDBC Update Operation is used to modify existing records in a database table. It is commonly performed using SQL UPDATE statements through JDBC APIs.

? Key Concepts

Used to modify existing data
Executed using executeUpdate()
Returns number of affected rows
Works with both Statement and PreparedStatement

? Syntax / Theory

The SQL syntax for update operation:

UPDATE table_name SET column1 = value1 WHERE condition;

? Code Example

? View Code Example

// JDBC program to update student record
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;

public class UpdateExample {
public static void main(String[] args) {
try {
// Load JDBC driver
Class.forName("com.mysql.cj.jdbc.Driver");

// Create connection
Connection con = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/college","root","password");

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

// Execute update query
int rows = stmt.executeUpdate(
"UPDATE student SET marks=85 WHERE id=1");

// Display affected rows
System.out.println(rows + " record updated");

// Close connection
con.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}

? Live Output / Explanation

Output

1 record updated

The output indicates how many rows were affected by the update query. If the condition does not match, the result will be 0.

? Interactive Simulation: Database Table

ID	Name	Marks
101	Alice Johnson	70
102	Bob Smith	88

UPDATE student SET marks = WHERE id = 101

✅ Tips & Best Practices

Always use WHERE clause to avoid updating all records
Prefer PreparedStatement to prevent SQL Injection
Close database resources properly
Handle exceptions carefully

? Try It Yourself

Update multiple columns in one query
Use PreparedStatement instead of Statement
Update records based on user input