Nowadays every action we do produces data like most computer applications. To this point moreover, some of these are reduced to managing and consulting data: our bank accounts, registrations, insurance, etc. This data is stored in what is called a file and is structured into records containing details such as our surnames, first names, date of birth, blood type, etc. More complex applications require data whose structure is also complex. The data is classified in several files according to the objects they describe: customer file, product file, order file, invoice file, etc. There are links between the files that reflect the relationships between the objects described. It also appears that the data necessary for an application could be useful to other applications, or even to other users. This data then constitutes what is called a database. Managing such data is no longer within the reach of elementary software. Guaranteeing the quality of the recorded data (can we find what was recorded?), their consistency (is the customer of each order listed?), protecting them in the event of an incident, allow several users to access them simultaneously, while strictly controlling access to confidential data, offering good access performance to all applications, in particular those that are interactive, are functions that require powerful and complex software like the database management systems, or DBMS such as SQL SERVER, MYSQL, ORACLE SQL. This type of software is one of the fundamental tools for the development of large computer applications thanks to these rules of integrity, namely the integrity of entities and referential integrity which allow the solidity and robustness of data, But these rules which must guarantee the essential security of the database for our various organizations are often violated by inattention or ignorance of these rules by the new developers and even by the old ones thus being able to involve many consequences on the whole of direct or indirect actors Keywords: Data, Integrity rules, DBMS

Data Integrity Rule Violations Entity Integrity Referential Integrity DBMS