Java Database Connectivity (JDBC)
What is Java Database Connectivity (JDBC)?
Java Database Connectivity (JDBC) is a Java-based data access technology that enables Java applications to connect to relational databases. It consists of a set of classes and interfaces that provide a standard API for establishing a connection to a database and executing SQL statements.
JDBC provides a standardized API for interacting with a database, regardless of the database vendor or type. This means that the same JDBC code can be used to connect to different databases, as long as there is a JDBC driver available for that database.
To use JDBC, you must first download and install a JDBC driver for the database you want to connect to. Then, you can use the JDBC API to create a connection to the database, send SQL statements, and process the results.
Here's a simple example of how to use JDBC to connect to a database and execute a SELECT statement:
import java.sql.*;
public class JDBCExample {
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver"; static final String DB_URL = "jdbc:mysql://localhost/test";
static final String USER = "username";
static final String PASS = "password";
public static void main(String[] args) {
Connection conn = null;
Statement stmt = null;
try{
Class.forName("com.mysql.jdbc.Driver");
System.out.println("Connecting to database...");
conn = DriverManager.getConnection(DB_URL,USER,PASS);
System.out.println("Creating statement...");
stmt = conn.createStatement();
String sql;
sql = "SELECT id, first, last, age FROM Employees";
ResultSet rs = stmt.executeQuery(sql);
while(rs.next()){
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last");
System.out.print("ID: " + id);
System.out.print(", Age: " + age);
System.out.print(", First: " + first);
System.out.println(", Last: " + last);
}
rs.close();
stmt.close();
conn.close();
}catch(SQLException se){
se.printStackTrace();
}catch(Exception e){
e.printStackTrace();
}finally{
try{
if(stmt!=null)
stmt.close();
}catch(SQLException se2){
}
try{
if(conn!=null)
conn.close();
}catch(SQLException se){
se.printStackTrace();
}
}
System.out.println("Goodbye!");
}
See Also