response database concepts integrity

Post 1. (Beverly) A relational database is based on the concept of relation and therefore, a relational database has integrity rules. This simply means that a relational database has its set design that it follows to construct a database based on relations. Relational database integrity rules are important when it comes to constructing a good database design (Carlos Coronel, 2020, p. 76). These rules of relational integrity are automatically enforced in the relational database management systems, but for extra support, it is recommended that the design conforms to the entity and referential integrity rules also.   

     In our text this week, entity integrity is defined as, the property of a relational table that guarantees each entity has a unique value in a primary key ad that the key has no null values (Carlos Coronel, 2020, p. 74).  A null is not a zero, it is the complete absence of any value. So, this would pose a problem in a relational model if the primary key were null.  Keeping with the rule of entity integrity will make sure that each entity is easily identifiable by a unique key or primary key.  Referential integrity is a condition by which a dependent table’s foreign key must have either a null entry or a matching entry in the related table (Carlos Coronel, 2020, p. 75). When you have two related tables in a relational database, it is referential integrity to have a foreign key that ensures the integrity of the database.  A foreign key links the two tables b taking the primary key of one table and placing it as an attribute in another table.  This will show the relation of both tables. 

     The two forms of data integrity, (entity and referential), added to the automatically implemented rational database integrity, are there to help join the storage of data that has been broken down in the relational database, to produce meaningful results.  These two integrities help to ensure that data will not get dropped or duplicated (Cooper, 2022).

 

REFERENCES

Carlos Coronel, S. M. (2020).  Database Systems. Boston: Cengage Learning, Inc.

Cooper, S. B. (2022, September 6).  Why Are Entity Integrity & Referential Integrity Important in a Database? Retrieved from Techwalla: https://www.techwalla.com/articles/why-are-entity-integrity-referential-integrity-important-in-a-database

 Post 2. (Adam)Entity integrity is a property of tables in relational databases that ensures each entity has its own primary key. This means that each row in the table has a unique identifier that you can use to reference that row. Further, the primary key has a second condition under entity integrity, it can not be a null value. If the primary key has no data, it is difficult to verify each row has its own identifier to call upon later.

   While entity integrity relies on the primary key, the concept of referential integrity relies on something called the foreign key. A foreign key is defined as a value from one table that matches the primary key of another table. For referential integrity, each tables foreign key should tie back to an entry in a related tables primary key. Every element tied to an entity is related to the other mentions of that element across the tables in the database.

   The domain is the set of possible values used for an attribute (Coronel & Morris, 2018). Since each column of a table is referring to the same attribute, you should have a domain to give a minimum and maximum value if you can. While there are cases were this doesn’t make sense like a person’s name, there are other cases like height where you can give a reasonable spectrum.

   The above factors contribute to the success of database design and implementation because they set you up for querying and drawing conclusions later. When you have all of your relationships established and data accurate, you can feel confident that you are getting good data. Having missing relationships or bad data from a domain violation is a surefire way to either miss out on data or get data that will lead to you drawing bad conclusions.

 

Reference:

Coronel, C., & Morris, S. (2018). Database Principles: Fundamentals of Design, Implementation, and Management. Cengage.