Data and databases: แบบฝึกหัด

In a relational database table, what is the term used for a single attribute of an entity, represented as a column in the table structure?

A database designer needs to ensure that a 'ProductID' field follows the format of exactly two letters followed by four digits (e.g., AB1234).

Which validation technique would be most appropriate to enforce this specific requirement?

A national retail chain uses a relational database to manage its inventory. The database contains a Stock table and a Warehouse table. Many different products can be stored in one warehouse, and a single product type can be distributed across multiple warehouses.

Which structural implementation would be most appropriate to resolve this relationship and ensure referential integrity while avoiding many-to-many complexities?

In a relational database, which term refers to a single row within a table that represents a complete set of data for one instance of an entity?

What is the main purpose of using a foreign key in a relational database table structure?

A database developer wants to ensure that a 'ProductPrice' field only accepts values between \(1\) and \(500\). State the type of validation rule that should be applied.

Describe the concept of data redundancy and identify one potential problem it causes in a database.

In SQL, which command is used to add a new record into an existing database table?

A library uses a relational database to manage its book collection and member loans. In this context, answer the following questions regarding database structure and data organization:

(a) Explain the difference between data and information using an example from the library system.

(b) The library uses a relational database. Identify and describe the role of a primary key and a foreign key in linking tables within this system.

(c) State the purpose of a composite key and provide an example of when it might be necessary in a library database.