Page 81 - iPro_trackGPT_V5_Class7
P. 81

TYPES OF DATABASES

                 There are mainly two types of databases:
                    Flat File Database: A flat file database is a simple type of database that stores
                    data in a single table or file, often as plain text or in a spreadsheet format.
                    Each record in the flat file is typically stored as a single line of text, with fields
                    separated by a separator (like commas or tabs). The most popular example of
                    a flat file database is Excel 2021.                                                    Excel 2021
                    Relational Database: This type of database stores data in multiple tables and links these tables
                    to retrieve related information. Commonly used relational database systems include Microsoft
                    Access, Microsoft SQL Server, ORACLE, etc.








                        Boost Bits


                  The concept of the relational database was introduced by Edgar F. Codd, who established a
                  set of thirteen rules, known as Codd’s Rules, to define a Relational Database Management
                  System (RDBMS).

                    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         Name                Father Name         Date of Birth       Class
                                                                                    15/08/2007
                                                                                                           VIII
                                                                Mr. K.S. Kant
                                            Krishna Kant
                             187/11
                       RECORDS  156/12      Rishi Sharma        Mr. N.K. Sharma     22/10/2008              IX
                             194/11
                                            Suraj Patel
                                                                Mr. G.S. Patel
                                                                                                            IX
                                                                                    16/04/2008
                             123/12
                                            Priyansh Sagar
                                                                Mr. P.K. Sagar
                                                         Table: Student's record    18/06/2007             VIII
                 The commonly used terms in a relational database are:
                    Table: In a DBMS, a table is also known as a relation. It organises related data into columns
                    and rows. Columns, also known as fields, represent categories of data such as Reg No, Name,
                    Father's Name, Date of Birth, and Class. Each field has a specific heading. A row in the table
                    represents a record, which is a complete set of values for these fields.
                    Primary Key: It is a unique field used to identify records uniquely within a table. A table can
                    only have one primary key. It ensures that each record can be uniquely distinguished from
                    others, preventing duplicate entries and maintaining data integrity. For instance,'Student's
                    record' the 'Reg No' can be referred to as a primary key as it is always unique and never null.
                    Query: A query is the most powerful object for retrieving information from a table based
                    on specific criteria or conditions. It allows you to find and extract data from the database by
                    creating and running the query.



                                                                          Database and DBMS—An  Introduction     79
   76   77   78   79   80   81   82   83   84   85   86