Database Theory

584 Words Jan 28th, 2018 2 Pages
Relationships on a database establish a connection between two associated and logically related tables, that each have similar data. An example may be a table that contains names of certain students, and another table that contains the student's ID, the code of library books, and the dates on which each specific student checked out that particular library book. Without association of relationship on the relational database, the two tables would be independent figures with librarian lacking a method for associating student with his/ her item. The library, accordingly, would have to close down in a short period of time. The database connection, on the other hand, allows a connection to be drawn between the Student's table and the Student's instrument table (that represents the books that the student checks out).
The database relationship also helps further improve table structure and reduce redundant data. With associated tables of information being connected, the user can improve both tables of related information simultaneously.
Finally, it helps the user derive data from two related tables simultaneously. With both tables being connected, the user can derive information form both tables simultaneously.

The purpose of a query in relational database.
Through the use of a query, a database pulls up the relevant item that may provide solution to your query. The function that it uses to do so is called a…
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