SQL SQL stands for Structure query language. This language is used to create, manipulate and manage database. There are many database software available for writing SQL. Some of the most famous Database Software are
- Microsoft SQL Server
- MySQL Server
- Microsoft Access
MAIN SQL Commands
Basic SQL is a really simple language, simpler than HTML. The commands are so simple, that you can even guess them.
For instance, if you want to create tables the command is CREATE Table. Similarly,
INSERT INTO is for inserting data into table
DELETE FROM is for deleting data from tables
SELECT FROM is for selecting or viewing data from tables
UPDATE is for updating data in tables
SQL Language has two main parts
- DDL (Data definition language) provides a medium of structural definition. Create, alter and drop.
- DML (Data Manipulation Language) – for manipulating data. Commands are Insert, Update, Delete
What is Database and Table?
A database is a large, organized collection of information. We store our Data in Database using Tables. Tables are containers that store data. They are composed of columns (vertically) and rows (horizontally).
You can think of database as a folder or as file cabinet. A database consists of one or many tables. It’s like a file cabinet consists of one or many files. Inside files there are pages, in the same way inside tables there is data. So the structure is like this
File Cabinet -> has files -> have Pages
Database -> has Tables -> have Data
For example, a database for a shopping cart website may have many tables for storing products, customers, orders.
What is DATA?
Data is a representation of facts, concepts or instructions in a formal manner suitable for communication, interpretation or processing by human beings or by computers. Data is stored in tables as rows and different information about the data subject as columns.
The software that handles our data or databases is known as RDBMS (Relational Database Management System). Examples of RDBS are ORACLE, MySQL, Microsoft SQL Server, Ms Access, DB2 and many more..
In RDBMS tables have relations with each other or in other words, tables are joined/connected with each other.
Mysql is a free RDBMS, it can be used with most of the web development language (for example Php, ASP, JSP). There are many tools available to use MySQL server, some of them are
- Command Line (DOS)
- Linux (Puttey)
- MySql Admin