How do I use JDBC to connect to a database?

How do I use JDBC to connect to a database?

To connect to a database using JDBC, you need to follow these steps: 1. Load the JDBC driver. 2. Establish a connection using DriverManager. 3. Create a Statement or PreparedStatement. 4. Execute your query. 5. Close the connection.

Can you show me a code example?

Sure! Here's a simple example:

import java.sql.*;

public class JdbcExample {
    public static void main(String[] args) {
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "user", "password");
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery("SELECT * FROM mytable");
            while (rs.next()) {
                System.out.println(rs.getString("column_name"));
            }
            conn.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

What if I want to use a different database?

You just need to change the JDBC URL and the driver class name according to the database you are using. For example, for PostgreSQL, use org.postgresql.Driver and the URL format jdbc:postgresql://host:port/database.

Are there any common issues I should be aware of?

Yes, common issues include:

1. Driver not found exception - ensure the driver is in your classpath.
2. Connection timeout - check your database server and network settings.
3. SQL syntax errors - verify your SQL queries.