Relational Database Management Systems_Unit2_DB

Relational Database Management Systems_Unit2_DB -...

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Relational Database Management Systems Unit 2 Discussion Board Kregg M. Soltow January 14, 2011 American Intercontinental University Research entity integrity and referential integrity; explain why they are important to relational databases. Entity integrity is an integrity rule that says every table must have a primary key and that those columns or single column chosen to be the primary key should be unique and not null.( Beynon-Davies,2004) The main result of this integrity regulation is that reproduced rows are not allowed in such tables. Now if every value of a primary key is distinctive, then there is no way that reproduced rows can show up in the table. The “not null” trait of a “primary key”, guarantees that any given assessment can be utilized to recognize each row in such a table. When speaking of referential integrity, all fields in a table assigned as a “foreign key” may consist of a value reflected in the parent tables “primary key”.( Beynon- Davies,2004) With this rule, removing documentation which consists of a value referred
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This note was uploaded on 02/17/2012 for the course ITCO 101 taught by Professor Gugenhiem during the Spring '12 term at AIU Online.

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Relational Database Management Systems_Unit2_DB -...

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