Database integrity
Encyclopedia
Database integrity ensures that data
entered into the database
is accurate, valid, and consistent. Any applicable integrity constraints
and data validation
rules must be satisfied before permitting a change to the database.
Three basic types of database integrity constraints are:
Data
The term data refers to qualitative or quantitative attributes of a variable or set of variables. Data are typically the results of measurements and can be the basis of graphs, images, or observations of a set of variables. Data are often viewed as the lowest level of abstraction from which...
entered into the database
Database
A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality , in a way that supports processes requiring this information...
is accurate, valid, and consistent. Any applicable integrity constraints
Integrity constraints
Integrity constraints are used to ensure accuracy and consistency of data in a relational database. Data integrity is handled in a relational database through the concept of referential integrity...
and data validation
Data validation
In computer science, data validation is the process of ensuring that a program operates on clean, correct and useful data. It uses routines, often called "validation rules" or "check routines", that check for correctness, meaningfulness, and security of data that are input to the system...
rules must be satisfied before permitting a change to the database.
Three basic types of database integrity constraints are:
- Entity integrityEntity integrityIn the relational data model, entity integrity is one of the three inherent integrity rules. Entity integrity is an integrity rule which states that every table must have a primary key and that the column or columns chosen to be the primary key should be unique and not null.A direct consequence of...
, not allowing multiple rows to have the same identity within a table. - DomainData domainIn data management and database analysis, a data domain refers to all the unique values which a data element may contain. The rule for determining the domain boundary may be as simple as a data type with an enumerated list of values....
integrity, restricting data to predefined data typeData typeIn computer programming, a data type is a classification identifying one of various types of data, such as floating-point, integer, or Boolean, that determines the possible values for that type; the operations that can be done on values of that type; the meaning of the data; and the way values of...
s, e.g.: dates. - Referential integrityReferential integrityReferential integrity is a property of data which, when satisfied, requires every value of one attribute of a relation to exist as a value of another attribute in a different relation ....
, requiring the existence of a related row in another table, e.g. a customer for a given customer ID.