JAVA DATABASE CONNECTIVITY (JDBC) || JDBC for Begginers

Sunday 30 June 2019

Common JDBC Component:

JDBC API - (java.sql, javax.sql)

Provides access to a relational database (like Oracle, SQL server, MySQL, etc.) from java.
Using JDBC API, frontend java application can execute query and fetch data from connected database.

Driver Manager:

This class manages a list of database driver.
JDBC driver Manager Interface defines 'objects' which are used to connect java application with different JDBC drivers.
JDBC Driver manager loads the most appropriate driver among all the drivers for creating a connection.

JDBC test suite:

JDBC test Suite is used to check capability of a JDBC driver with J2EE platform.
JDBC-ODBC bridge:
As the name suggests this enables JDBC access via ODBC drivers.
The JDBC Driver contact to the ODBC Driver for connection ti the database.
The ODBC driver is already installed or come as deafult driver in windows.

JDBC Architecture:

The JDBC API supports both two-tier and three tier processing model for database access but in general, JDBC Architecture consist of two layers:
1. JDBC API: This API provides the Application-to-JDBC Manager connection.
2. JDBC Driver API: This supports the JDBC Manager-to-driver Connection.
The JDBC API uses a driver manager and database specific drivers to provide connectivity to database.
The JDBC driver manager ensure that the Correct driver is used to access each data Source.
The Driver manager is capable of supporting multiple concurrent drivers connected to multiple databases.

Two tier database design:

The two-tier is based on Client-Server architecture.
The direct Communication takes place between client and server.
There is no mediator between client and server.
In this type of Database design, User Interface and business Logic is in client side and Database is on server side.
The client computer directly access the data without seeing the database. This means that the data on the server is much more secure.

Advantages:

Disadvantages:

Three tier database design:

In this type of Database design, User interface is on client side, Business Logic is on separate application server and database is on Database Server.
In three-tier database design, client communicates with database server through application server.
Three-tier architecture typically have Presentation tier, Business tier or data access tier, and data tier.
Three layers in the three tier architecture are as follows:

1. Client layer(Presentation layer)
2. Business layer(Application layer/Middle layer)
3. Data layer

Client layer:

It is also called as presentation layer which contains UI part of our application.
This layer is used for the design purpose where data is presented to the user or input is taken from the user.

Business layer:

In this layer all business logic written like validation of data, calculation, data insertion etc.
It acts as an interface between client layer and data layer.
It is also called the mediator, helps to make communication faster between client and data layer.

Data layer:

In this layer actual database is comes in the picture.
It contains method to connect with database and to perform insert, update, delete, get data from database based on our input data.

Advantages:

Disadvantages:

Introduction: JDBC

JDBC (Java Data Base Connection) is the standard method of accessing database from java Application.
JDBC is a Java API for executing SQL statements. (standard for java Database connectivity.)
JDBC is a platform independent interface between relational database and java application.
The combination of Java and JDBC makes it possible for a programmer to "write it once and run it anywhere."
JDBC consist of a set of classes and interfaces written in java for connectivity.