17 Oct Defining relationships within a database can improve search ?capabilities and optimal performance of the database in the long run. Identify at least two relationship strength types that
Defining relationships within a database can improve search capabilities and optimal performance of the database in the long run.
- Identify at least two relationship strength types that can be used within the entity relationship model.
- Provide a real-world scenario that demonstrates each relationship strength classification, using the classifications.
- Be sure to respond to at least one of your classmates' posts.
Kwadwo Sarfo
RE: Week 2 Discussion
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Hi Professor and class
There are several different types of relationships. The most common are the one-to-one, one-to-many, and many-to-many relationships.
· One-to-One Relationships. In a one-to-one relationship, each record in the first table represents only one record in the second table. A good example of this type of relationship is a bank account that has a unique customer number as its primary key and an account balance as its foreign key. A real-world example of a one-to-many relationship is a bank account that has a unique customer number as its primary key and an account balance as its foreign key. The primary key, customer number, is unique for each customer, so each record in the first table represents only one record in the second table. However, every bank account will have multiple transactions and thus multiple transaction amounts. In this example, the relationship strength between the two tables is one-to-many because each customer can have many transactions but each transaction belongs to only one customer.
· One-to-Many Relationships. A one-to-many relationship occurs when each record in the first table can be associated with more than one record in the second table. A good example of this type of relationship is an employee who has multiple phone numbers associated with him or her. In a real-world scenario, we can look at the relationship between an organization and its employees. For example, each employee in the organization has a unique ID number, which is used to track his or her employment history. In addition, each employee may have multiple phone numbers associated with him or her. This is an example of a one-to-many relationship. The first table (employee) is considered the "one," and the second table (phone numbers) is considered the "many."
· Many-to-Many Relationships. In a many-to-many relationship, each record in the first table can be associated with multiple records in the second table and vice versa. An example of this type of relationship would be orders placed by customers for products that have multiple suppliers that supply those products to various customers throughout time. A classic example of a many-to-many relationship is inventory management. A product can have multiple suppliers and vice versa. For example, if you have an online store selling electronics, you might need to keep track of all your suppliers who provide various products that are sold by your company.
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