JDBC is a set of Java API for executing SQL statements. This API consists of a set of classes and interfaces to enable programs to write pure Java Database applications.
JDBC stands for Java Database Connectivity. It is a Java API (Application Programming Interface) that allows Java programs to interact with databases. JDBC provides a standard interface for connecting Java applications with relational databases, such as MySQL, Oracle, PostgreSQL, and others.
Key features of JDBC include:
- Database Connectivity: JDBC enables Java applications to connect to a database, establish a connection, and perform database operations.
- Driver Manager: JDBC uses a Driver Manager to manage a list of database drivers. The driver is a software component that translates Java calls into database-specific calls.
- Connection: JDBC helps establish a connection to a database. The
Connection
interface provides methods for creating statements, committing or rolling back transactions, and managing the connection itself. - Statement: JDBC supports different types of statements for executing SQL queries and updates. The two main types are
Statement
andPreparedStatement
.PreparedStatement
is preferred for executing parameterized queries to improve performance and prevent SQL injection. - ResultSet: After executing a query, JDBC provides the
ResultSet
interface to retrieve and process the results.
Here’s a simple example of JDBC code to give you an idea:
import java.sql.*;
public class JDBCExample {
public static void main(String[] args) {
// Database URL, username, and password
String url = “jdbc:mysql://localhost:3306/mydatabase”;
String user = “username”;
String password = “password”;
try {
// Establish a connection
Connection connection = DriverManager.getConnection(url, user, password);
// Create a statement
Statement statement = connection.createStatement();
// Execute a query
ResultSet resultSet = statement.executeQuery(“SELECT * FROM mytable”);
// Process the results
while (resultSet.next()) {
System.out.println(resultSet.getString(“column1”) + “, “ + resultSet.getString(“column2”));
}
// Close resources
resultSet.close();
statement.close();
connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
This example shows the basic steps of connecting to a database, executing a query, and processing the results using JDBC. Keep in mind that handling exceptions and closing resources properly is important in real-world applications.