There are multiple
books written on database design rules and different normal forms but it’s very
difficult for a beginner to understand those and derived what is required. So
to ease beginner problem I am trying to simplify what is required to start programming
and understanding database.
When we say
database is collection of data the questions comes how it’s different from
files. I hope everyone understand the data files. Data files hold data in file
format which you can store on your hard drive and can access by opening it. While
database is enhance version of this where there is the system which holds the
data in special format and it can’t be access by anyone just like that. For
accessing it you need to understand the particular database accessing language
which is TSQL in case of SQL Server.
Like many other database the SQL Server is the
technology given by the Microsoft for data related operations. ANSI has
provided basic rules for data related operation which is termed as SQL. On
using basic fundamentals of SQL other companies has designed their specific
language like TSQL for SQL Server ,PLSQL for oracle etc.
And big joke is if
you ask anyone do you know SQL then answer will yes, but when you ask them
which SQL they will not able to tell whether they know TSQL or PL/SQL etc.
Coming back to our
topic we need to understand the SQL Server as a system which holds database and
perform multiple operations related to database.
In SQL Server a
Database contains multiple tables to hold data as per the SQL gods the columns
are termed as attribute and rows are values assigned to those attribute and we
can say table is an entity.
For Example I want
to store the details of my Family below are the points which I will maintain as
data.
Family Member Name,
Age, DOB and Mobile no will be the columns against which the information will
be stored.
Here we will create
a table family member which will be act as entity and the columns will be the
attribute of that entity. The rows which will get entered or added will be the
detail and you can say data for that entity.
In the next
chapters we will understand database design steps and relations between tables
then later on creating data models which is most important part of learning
SQL.
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