Creating a Database in Access

Creating a Database in Access

Entity integrity is any data placed in a database record. This data is not duplicated nor has no null value. The primary key is the core entity integrity which is unique and must have a value, not allowing null valves (IBM, 2005, p. 1). Example of this is a product is entity the product table represents the idea of each item placed in that table is specific product. The best way to setup a table is with a primary key to identify each product in that table. This term is called entity integrity constraints. You would place a unique id to each product making a primary key.

Referential integrity is a relationship between two or more tables. Each table has a primary key in a database so if you need to link one table to another table you would use a foreign key which was a primary key in the other table (Chapple, 2005, p. 1). Example is in vendor table and the product table which we did in unit 1 IP. The product table had a primary key of SKU ID or Product ID but you put the primary key from the vendor table such as Vendor ID as a foreign key in the product table to link them together. Foreign keys join tables and establish dependencies between the tables.

These keys are important to a relational database for a number of different reasons. One reason is that integrity is important which does not allow duplicating information. Classify and defining integrity by using a primary key for the data. These help the user to define and select data in the database. Referential integrity is also important to the user and creator to maintain and retrieve information from the database, cutting down on errors. The program would give an error if any type of primary key was deleting or remove from the database. This rule does not allow any user to cause major problems defining the integrity of the database.

References

Chapple, M. (2005). Referential Integrity. Retrieved from http://databases.about.com/cs/administration/g/refintegrity.htm

IBM. (2005). Entity Integrity. Retrieved from http://publib.boulder.ibm.com/infocenter/idshelp/v10/index.jsp?topic=/com.ibm.sqlt.doc/sqltmst157.htm