JDBC in Java

Introduction

• JDBC stands for Java DataBase Connectivity

• It is based on run time polymorphism

• It is standard API for java apps to interact with database and perform operations ; API means pre-defined classes and interfaces in Java

• We need to use Driver for connecting JDBC API and the database.

• Drivers are database dependent, meaning each database have their own driver and maintained by the database company.

• In our case, I am using MYSQL DB, and it’s driver is nothing but a JAR file (mysql-connector.jar)

Important Classes and Interfaces while using MYSQL Database

• java.sql.DriverManager

• java.sql.Connection

• java.sql.Statement

• java.sql.PreparedStatement

• java.sql.Callable

• java.sql.ResultSet

• java.sql.SQLException

Connecting MYSQL Database with Java

• Here Driver interacts with JDBC API and the Database

• I am using IntelliJ IDE here. So to load the Driver in your current directory follow below steps:

  File → Project Structure → Modules → Dependencies → + → JARs or directories → select mysql-connector-j-8.x.x.jar → Apply

• Steps to connect to mysql database:

  1. Load the Driver:

     Class.forName(”com.mysql.jdbc.Driver”)

  2. Create connection

     DriverManager.getConnection(”url”,”username”,”pwd”)

  3. Create query, Statement {for Static Queries}, PreparedStatement {for Dynamic Queries}, CallableStatement

     createStatement() ,execute(), executeUpdate(), executeQuery(), Resultset

  4. Process the Data

     getInt(), getString() —> column no. or column name within the paranthesis

  5. Close the connection

     .close()

Note: Ensure you have already created the database which you are trying to connect here.