Advance Database Lesson1

SQL

a flexible computer language that you can deploy in different ways to communicate with relational databases

Single Tier Architecture

the Client, Server, and Database all reside on the same machine

Two Tier Architecture

 interface which is called ODBC (Open Database Connectivity) an API which allows the client-side program to call the DBMS. Today most of the DBMS offers ODBC drivers for their DBMS.

1.Presentation layer runs on a client (PC, Mobile, Tablet, etc)

2. Data is stored on a Server.

Three Tier Architecture

1.  Presentation layer (your PC, Tablet, Mobile, etc.)

2. Application layer (server)

3.  Database Server

Schema

description of a database, which is specified during database design.

Instances

The data in the database at a particular moment in time is called a database state or snapshot. It is also called the current set of occurrences or instances in the database.

Data Definition Language

used for specifying the database schema. It is used for creating tables, schema, indexes, constraints etc. in database. Lets see the operations that we can perform on database using

CREATE

ALTER

DROP

TRUNCATE

RENAME

DROP

COMMENT

Data Manipulation Language

is used for accessing and manipulating data in a database. The following operations on database

SELECT

INSERT

UPDATE

DELETE

Data Control Language

is used for granting and revoking user access on a database

Transaction Control Language

The changes in the database that we made using DML commands are either performed or rollback

Commit and Rollback