Showing posts from April, 2023

what are the 12 codd's rule

  What are the twelve codd’s rule   Codd’s rules are a set of guidelines and principels that define the characteristics that define the characteristics that relational database management system (RDBMS) must meet to be considered a truly rlational database. Here are the 12 Codd’s Rules:   Rule 0: The Foundation Rule A relational DBMS must be able to mange its data entirely trough its relational capabilities. Rule 1: Information rule All data in a relational database is to be represented in one and only one way, namely by values in tables. Rule 2: Guaranteed Access Rule Each and every data element (atomic value) is guaranteed to be accessible logically with a combination of table name, primary key value, and column name. Rule 3: systematic Treatment of Null values Null value are treated uniformly and systematically. Rule 4: Dynamic online catalog Based on the Relational model The database schema must be stored in the same relational format as regular data. Ru
  what is Database and types of Data.          Database: A database is an organized collection of data that can be accessed,managed,and updated quikly and easily. In a database management system (DBMS), the data is stored in tables with each table consisting of columns and rows. The DBMS software manages the data and allows to perform various operations on the data,such as adding,updating, and deleting data.   Types of data: 1)Relational database: This type of database stores data in tables that are related to each other through common fields, examples of relational databases include MySQL, Oracle, and SQL server. 2)Object-oriented database: This type of database stores data as objects,which can manipulated using programming languages such as java or c++. Examples of object-oriented databases include objectDB and versant. 3)Quantitative data: Quantitative data can be observed and recorded. This data type is non-numerical in nature. This type of data collected through met