What is JDBC in Java?

Direct Answer

JDBC is Java's standard API for connecting to data sources, executing SQL, controlling transactions, and reading results. Vendors provide drivers behind common interfaces. The API makes code structure more portable, but changing databases often requires changes to the JDBC URL, SQL dialect, types, generated keys, and behavior; the same code is not guaranteed to work after only swapping a driver.

Code Example

// JDBC: program against interfaces; the driver implements them
String url = "jdbc:mysql://localhost:3306/shop";
try (Connection con = DriverManager.getConnection(url, "user", "pass");
     PreparedStatement ps = con.prepareStatement("SELECT name FROM users WHERE id = ?")) {
    ps.setInt(1, 42);
    try (ResultSet rs = ps.executeQuery()) {
        if (rs.next()) System.out.println(rs.getString("name"));
    }
}
// Connection, PreparedStatement, ResultSet are JDBC interfaces;
// the MySQL driver provides the concrete classes.

Common Mistakes & Pitfalls

• Thinking JDBC talks to the DB directly: it calls a vendor driver that does the talking.
• Missing the driver dependency: no driver JAR → No suitable driver error.
• Not closing resources: leaking Connection/ResultSet exhausts the pool.
• Confusing JDBC with JPA: JDBC is the low-level API; JPA/Hibernate sit on top of it.