Core JDBC Interfaces

Direct Answer

The main JDBC interfaces include Driver, Connection, Statement, PreparedStatement, CallableStatement, ResultSet, and DatabaseMetaData. DataSource is a javax.sql interface used to obtain connections. DriverManager is an important utility class, not an interface. JDBC code targets these contracts while a driver supplies most concrete implementations.

Code Example

DataSource ds = ...;                                  // DataSource
try (Connection con = ds.getConnection();             // Connection
     PreparedStatement ps =                             // PreparedStatement
         con.prepareStatement("SELECT name FROM users WHERE id = ?")) {
    ps.setLong(1, 7L);
    try (ResultSet rs = ps.executeQuery()) {           // ResultSet
        if (rs.next()) System.out.println(rs.getString("name"));
    }
}
// Every type above is an interface; the JDBC driver supplies the classes.

Common Mistakes & Pitfalls

• Treating them as classes: they're interfaces implemented by the driver.
• Confusing the Statement subtypes: Statement (static), PreparedStatement (params), CallableStatement (procedures).
• Forgetting DataSource: it's the modern entry point, not DriverManager.
• Assuming ResultSet is scrollable: it's forward-only by default.