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What is a one-to-many relationship?
It is a term from computer databases. A relational database can have a one-to-many relationship in its data. For example, if you have a customer order database, one table will contain customer names and another will contain their orders. Each customer will only be listed once, but each customer can make many orders. So one customer can be related to many orders. Incorporating that into a database requires the creation of a one to many relationship.
What are the various reasons that lead to the occurrence of NULL values in relations?
A given field in a database table might be for a values that, in certain case, no such values exist or can be determined. For example, in an employee database, a field might be a foreign key to that employee's direct manager. However, in the case of the CEO, there is no such person. In that case, the field would be set to Null.
What is the ranges of database?
ranges of database
What are anomalies in database?
Anomalies is the data within the database; it is the copy of the original data it needs to be updated in order to avoid problems such as viewing the website. There are four types of anomalies which are Insertion anomaly, Deletion anomaly, Duplicate entry and Modify (Update anomaly). Insert anomaly is the entity that relates to another entity within the table. If the data doesn't relate to another entity then there is no point of entering it, therefore a unique data is needed to identify a particular data to insert the data that relates with it such as employee ID number. Example of insert anomaly: If any company's manager need to insert their employee salary to the employee's ID, they then need to make sure that the employee id is correct otherwise, if it's wrong then they will give unfair salary to their employee by which they will have bad name onto their company.
What is the definition of database clustering?
Database is defines as a collection related records/data. When the data in the database is grouped based on some classification it is called database clustering.
What is Entity instances?
Entity instance is a single occurrence of an entity type. Also known as an instance. Unlike entity type, many instances of entity type may be represented by data stored in the database.
What is entity occurrence?
An entity occurrence is essentially an instance of an entity. A great example of an entity occurrence is someone's birthdate and other personal records.
A is anything about which data are to be collected and stored?
A can be defined as the subject or entity for which data are being collected and stored. It can represent any element, person, product, or event that is being recorded and analyzed within a dataset. In data collection, A serves as the focal point for gathering information and insights.
Why do we need weak entity sets?
why do we need weak entity in database when we can make it strong entity?
What is difference between object and entity?
A database object is represented as one of the following: database, schema, table, column, primary key, and foreign key A database Entity is: An entity is a thing or object of importance about which data must be captured. All things aren't entities - only those about which information should be captured. Information about an entity is captured in the form of attributes and/or relationships. If something is a candidate for being an entity and it has no attributes or relationships, it isn't an entity. Database entities appear in a data model as a box with a title. The title is the name of the entity.
Entity-relationship model of hospital mis?
entity relation model for hospital database
A schematic of the entire database that describes the relationships in a database is called?
entity-relationship diagram.
What is a simple key in database?
A simple key consists of a single attribute to uniquely identify an entity occurrence, for example, a student number, which uniquely identifies a particular student. No two students would have the same student number.
What are the basic components of database?
Entity Attribution Relationship
What is all of the fields for a single database entity?
Record
What is entities database?
Entity means a specific thing in both database work and data modeling. An entity is data that can be classified, and has a relationship with other classified data, as in entities.
What is all of the fields for a single database entity called?
Record
