First Normal Form (1NF) | Database Normalization | DBMS

hello everyone welcome back to study tonight calm in our last video we studied about the basic concept of normalization we saw and understood how data redundancy can lead to several issues and how normalization can reduce data redundancy and make the data more meaningful in this video we will learn about the first normal form which is like the step 1 of the normalization process the first normal form expects you to design your table in such a way that it can easily be extended and it is easier for you to retrieve data from it whenever required if a table or a database is not even in first normal form it is considered as bad database design so we can say first normal form is the basic requirement and to follow this should become your default nature while creating tables to store data also it is step 1 to move on to second and third normal form the first normal form expects you to follow a few simple rules while designing your database and they are rule number one each column of your table must be single valued which means it should not contain multiple values we will explain this with help of an example later let's see the other rules for now rule number two this is more of a common-sense rule in each column the value stored must be of the same kind for example if you name a column date of birth to save date of births of a set of people then you cannot or you must not save names of some of them in that column along with date of births of others in that particular column it should hold only date of birth for all the entries of those rule number 3 expects each column to have a unique name this is to avoid confusion at the time of retrieving data if one or more columns have same name the DBMS system will be left confused rule number 4 says that the order in which you stored the data in your table doesn't matter although all the rules are self-explanatory still let's take an example where we will create a table to store student data which will have students roll number their name and the name of subjects they have opted for so we will be creating a table with three columns we can obviously have as many columns in a table as we want but for our example we only need three we will name the columns roll number name subject let's add some data to our table now with data added our table already satisfies three rules out of the four rules as all our column names are unique we have stored data in the order we wanted to and we have not mixed different types of data in our columns but out of the three different students in our table to have opted for more than one subject and we have stored the subject names in a single column but as per first normal form each column should contain atomic values now how to solve this problem it's very simple because all we have to do is break the values into atomic values by doing so although few values are getting repeated but values for subject column is now atomic for each row hence a table is in first normal form

Channel: Studytonight with Abhishek

Views: 1,049,132

Keywords: dbms, database normalisation, dbms tutorial, 1st normal form, 1NF dbms, 1NF, first normal form, 1nf for beginners, 1nf with example, simple 1nf explanation, database normalization, 2NF, 3NF, BCNF

Id: mUtAPbb1ECM

Length: 3min 42sec (222 seconds)

Published: Sun Dec 24 2017