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Relational Data Model
                 This data model is based on the principle of setting relationships between two or more tables of the same database.
                 It is the most used database model. The relational database model was proposed by Edgar F. Codd in 1970. Relational
                 database model is the most common type of database model. In the relational database model, data is organised
                 into tables, with each table consisting of rows and columns. Each row represents a record or entity, and each column
                 represents a specific attribute or field of that entity. The data in different tables are related with common fields. So,
                 relations are set between tables based on common fields. That is why this model is termed as relational database
                 model. These relationships enable the database to maintain data integrity and enforce constraints such as referential
                 integrity.

                 By storing related data in separate tables and establishing relationships between them, the relational model allows for
                 efficient data organisation, retrieval, and manipulation. This model’s flexibility and scalability make it one of the most
                 widely used and versatile database models in various industries and applications.
                 The difference among hierarchical, network, and relational data models is shown in the following table:

                  S. No.    Hierarchical Data Model          Network Data Model              Relational Data Model
                    1     Data is organised in a tree-like  Like the hierarchical  model  but  Data is represented in  tables
                          structure,  with  parent-child  with more flexible relationships.  consisting of rows and columns.
                          relationships.
                    2     Each child  node  has  exactly  Nodes can have  multiple  parent  It’s based  on  mathematical  set
                          one parent node.             nodes, allowing for more complex  theory and predicate logic.
                                                       connections.
                    3     It’s primarily used in older  It uses pointers to represent  Relationships between tables are
                          database systems.            relationships between records.  established  using keys,  primarily
                                                                                       primary and foreign keys.
                    4     It is rigid in structure and is not  Developed as an improvement over  Offers flexibility and scalability,
                          suitable for applications  with  the hierarchical model but still has  making it widely adopted in modern
                          evolving  data structures  or  limitations  in  terms  of complexity  database systems.
                          complex relationships.       and scalability.
                    5     Querying hierarchical data can  Querying  in  the  network  data  Querying  is  simplified  with  SQL
                          be complex due to its rigid  model  can be more complex  (Structured Query Language) which
                          structure.                   compared to the relational model. provides a standardised  way  to
                                                                                       retrieve and manipulate data.



                         RELATIONAL DATABASE MANAGEMENT SYSTEM (RDBMS)

                 RDBMS is an advanced form of Database Management System and is based on a Relational Model. In this model, a
                 relational database has a set of related tables that are interlinked to each other based on a common field. It is a very
                 efficient way of representing data and allows data in a table to be represented in a two-dimensional form and is known
                 as a Relation. A row in a relation is called Tuple or Record. It is a collection of related data fields. Each tuple uniquely
                 identifies a record based on a unique key-known as Primary key. Data from different relations can be easily extracted
                 as they are interlinked based on a Primary key. A column in a relation is called an Attribute or Field. It store similar
                 data type value.

                 Structured Query Language (SQL) is the standard language for managing relational databases and performing various
                 operations on the data in the tables. It would enable us to store, retrieve, and manipulate data in the tables.




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