Page 86 - Trackpad_ipro 4.1_Class7
P. 86

TYPES OF DATABASES

                  There are mainly two types of databases:

                     Flat File Database: It is a type of database that contains records having a
                     less number of fields without any structured relationship between them. The
                     most popular example of a flat file database is Excel 2019.
                     Relational  Database: It is a type of database that  stores data  in several

                     tables and links those tables together to get a common piece of information.
                                                                                                             Excel 2019
                     Commonly used relational database systems are Microsoft Access, ORACLE,
                     Microsoft SQL Server, etc.









                   Clickipedia



                    The  relational  database was  proposed  by  Edgar F.  Codd.  He  gave  a  set  of  thirteen  rules
                    (Codd’s rules) to define a Relational Database Management System.

                      TERMS RELATED TO A DATABASE

                  Data is stored in the table of a database, as shown in the diagram given below.

                                                                 FIELDS
                      Primary key

                                Reg No. Student's Name Father’s Name               Date of Birth       Class
                                187/11     Krishna Kant        Mr. K.S. Kant       15/08/2007             VIII
                           RECORDS  156/12  Rishi Sharma       Mr. N.K. Sharma     22/10/2008              IX


                                194/11
                                           Suraj Patel
                                                                                   16/04/2008
                                                                                                           IX
                                                               Mr. G.S. Patel
                                123/12     Priyansh Sagar      Mr. P.K. Sagar      18/06/2007             VIII
                  The commonly used terms in a relational database are:
                     Table: Table is also knowns as Relation. It is a group of related data organised in columns
                     and rows in a database. The columns contain a number of headings such as Reg No., Name,

                     Father's Name, Date of Birth, Class, etc. These columns are also known as a Fields. A set of
                     values for the fields is called a Record. A record is one row of the table.
                     Primary Key: It is a unique field by which the records are uniquely identified in a table. A table
                     can have only one primary key. For example, in a table 'Student's detail' the 'Reg No.' can be
                     referred to as primary key.
                     Query: A query is the most powerful object in a database. It helps you retrieve information

                     from a table based on some criteria or conditions. You can find, and retrieve data from the
                     database just by creating and running the query.


                    84     iPro (Ver. 4.1)-VII
   81   82   83   84   85   86   87   88   89   90   91