Notes – JDBC in Advanced Java

JDBC stands for Java Database Connectivity. It is a Java API that allows Java applications to interact with databases.

JDBC provides a standard way to connect, query, update, and manage data from relational databases like MySQL, Oracle, PostgreSQL, etc.

To connect Java applications with any relational database
To perform database operations like:
- Insert, Update, Delete, and Retrieve data
To write platform-independent database code

Layer	Description
Application Layer	Java program written by the developer
JDBC API	Interfaces and classes like `Connection`, `Statement`, `ResultSet`
JDBC Driver	Translates JDBC calls into database-specific calls
Database	The actual relational database like MySQL, Oracle, etc.

Component	Purpose
`DriverManager`	Manages JDBC drivers and establishes connection
`Connection`	Represents a session with the database
`Statement`	Executes static SQL queries
`PreparedStatement`	Executes precompiled SQL with input parameters
`ResultSet`	Stores the result of SQL queries (like SELECT statements)

Load the Driver
Class.forName("com.mysql.cj.jdbc.Driver");
Establish Connection
Connection con = DriverManager.getConnection(dbURL, username, password);
Create Statement
Statement stmt = con.createStatement();
Execute Query
ResultSet rs = stmt.executeQuery("SELECT * FROM users");
Process Result
while(rs.next()) { ... }
Close Connection
con.close();