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  2. Referential integrity - Wikipedia

    en.wikipedia.org/wiki/Referential_integrity

    Referential integrity is a property of data stating that all its references are valid. In the context of relational databases , it requires that if a value of one attribute (column) of a relation (table) references a value of another attribute (either in the same or a different relation), then the referenced value must exist.

  3. Data integrity - Wikipedia

    en.wikipedia.org/wiki/Data_integrity

    Data integrity is normally enforced in a database system by a series of integrity constraints or rules. Three types of integrity constraints are an inherent part of the relational data model: entity integrity, referential integrity and domain integrity. Entity integrity concerns the concept of a primary key. Entity integrity is an integrity ...

  4. Foreign key - Wikipedia

    en.wikipedia.org/wiki/Foreign_key

    Because the database management system enforces referential constraints, it must ensure data integrity if rows in a referenced table are to be deleted (or updated). If dependent rows in referencing tables still exist, those references have to be considered. SQL:2003 specifies 5 different referential actions that shall take place in such ...

  5. Virtuoso Universal Server - Wikipedia

    en.wikipedia.org/wiki/Virtuoso_Universal_Server

    Virtuoso ORDBMS database supports entity integrity and referential integrity. Virtuoso ensures that relationships between records in related tables are valid by enforcing referential integrity. Integrity constraints include: NOT NULL – Within the definition of a table, Virtuoso allows data to contain a NULL value. This NULL value is not ...

  6. Entity integrity - Wikipedia

    en.wikipedia.org/wiki/Entity_integrity

    Entity integrity is concerned with ensuring that each row of a table has a unique and non-null primary key value; this is the same as saying that each row in a table represents a single instance of the entity type modelled by the table.

  7. Codd's 12 rules - Wikipedia

    en.wikipedia.org/wiki/Codd's_12_rules

    Codd's twelve rules [1] are a set of thirteen rules (numbered zero to twelve) proposed by Edgar F. Codd, a pioneer of the relational model for databases, designed to define what is required from a database management system in order for it to be considered relational, i.e., a relational database management system (RDBMS).

  8. Third normal form - Wikipedia

    en.wikipedia.org/wiki/Third_normal_form

    A database relation (e.g. a database table) is said to meet third normal form standards if all the attributes (e.g. database columns) are functionally dependent on solely a key, except the case of functional dependency whose right hand side is a prime attribute (an attribute which is strictly included into some key).

  9. Category:Database management systems - Wikipedia

    en.wikipedia.org/wiki/Category:Database...

    A database management system (DBMS) is a computer program (or more typically, a suite of them) designed to manage a database, a large set of structured data, and run operations on the data requested by numerous users. Typical examples of DBMS use include accounting, human resources and customer support systems.