WS WhereIsStuff
Tutorial Guides
Log In Sign Up

Advertisement

Google Ad Slot: content-top

JDBC Introduction

Previous Next

What is JDBC?

JDBC (Java Database Connectivity) is an API (Application Programming Interface) that allows Java applications to interact with databases. It provides methods to connect, execute queries, retrieve data, and manipulate databases using Java code.


Why is JDBC?

Java applications need a way to communicate with databases like MySQL, PostgreSQL, Oracle, and SQL Server. JDBC acts as a bridge between Java programs and relational databases.

JDBC Process (Step-by-Step):

To interact with a database using JDBC, follow these 5 steps:


1. Import JDBC Packages

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

2. Establish Connection

Use the DriverManager.getConnection() method.

Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "root", "password");

3. Create a Statement

A Statement object is used to execute SQL queries.

Statement stmt = con.createStatement();

4. Execute SQL Query

Use executeQuery() for SELECT statements and executeUpdate() for INSERT, UPDATE, DELETE.

ResultSet rs = stmt.executeQuery("SELECT * FROM students");

5. Process the Results

Retrieve data from the ResultSet object.

while (rs.next()) {
System.out.println(rs.getInt("id") + " " + rs.getString("name"));
}

6. Close the Connection

Always close database connections to free up resources.

con.close();
Example
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "root", "password");
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM students");
while (rs.next()) {
System.out.println(rs.getInt("id") + " " + rs.getString("name"));
}
con.close();

Previous Next