Skip to main content

Posts

Showing posts from March, 2023
     RDBMS RDBMS: It stands for relational database management system so the data is stored in the form of the relational model The RDBMS is developed by CODD   when he was working at IBM company in the year 1970 so CODD came up with one decision he decided that any information must come to the table CODD'S RULES  If we satisfy more than 7 rules we can say it is a relational database model RULE NO 1:- INFORMATION RULE  Every  information must be in the form of rows and columns only any kind of information that must be displayed the basics of  information RULE NO 2:- GUARANTEED ACCESS RULE It means every piece of information must be accessed and have permission to read and make changes  Every single data element (value) is guaranteed to be accessible logically with a combination of the table name, primary key (row value), and attribute name (column value). RULE NO 3:-SYSTEMATIC TREATMENT OF NULL VALUES The NULL values in a database must b...