In this article we will learn what is sql and understand all the basic concept of sql like database design, table design, assign key to columns…
Before we start to learn any thing about database and table design, first we should learn what is SQL.
What is SQL ?
SQL means Structured Query Language is used to access and modify information or data from a database. In other language we can say SQL is a query language used to accessing and manipulating information or data in table of a database.
SQL is the query language for relational database management systems.
SQL statements are used to perform tasks on database table like insert data into database, retrieve data from a database and update data in to database.
Most common database system that use sql are Oracle, Microsoft SQL – Server, Microsoft Access.
What is Database Management System ?
DBMS ( Database Management system) is a tools or software that manages the database. DBMS is the system where we can create and manipulate databases.
The Microsoft SQL – Server, Oracle, Access all are the example of DBMS.
The DBMS is the place which provide user friendly environment for creating and managing database.
The next step to learn what is database and table.
What is Database?
A database is a collection of information that is well organized so we can easily accessed, managed, and updated.
Database is a place where we can store our data for permanently and we can retrieve and managed as per our needs.
A database has a many tables for storing information by columns and row wise. We can also say a database is a collection of tables.
What is Table ?
A Database contains number of tables.
A databases store data or information in tables. A table constructed of a number of columns. Each columns created with specific data type and size.
What is Table Columns?
A Table is designed with a number of columns, a column name displays top of the table.
A Columns have specific data type and size declared as time of creating columns. Data type specify the types of data we can store in table. A data type may be int, chat, numeric, text… etc.
suppose we create table for Student the columns RollNo should be int type and StudentName should be text data types.
What is Table Rows?
A table rows contains the record or information according to the columns data type.
In Student table the RollNo Columns have all int values store in rows and in StudentName records should be the text type data.
In next asp.net post we will learn about SQL Statements : DDL Statements and DML Statements