Elements of a relational database

There are several elements that work together to form the foundation of a relational database, allowing users to store, organize, and retrieve data in a structured and efficient manner. These elements include:

• Tables contain a structured set of data with rows and columns. Each table stores data about a specific subject, like customers, orders, or products in an e-commerce store.
• Columns, also known as attributes or fields, define a table's structure by specifying the type of data each entry will hold.
• Rows, often referred to as records or tuples, represent individual entries in a table. Each row contains a collection of values corresponding to the columns.
• Keys are columns or a set of columns that uniquely identify rows within a table.
• Primary key guarantees that no two rows will have the same value for the primary key column. A table can only have one primary key. For example, customer ID can be a primary key, as no two customers will have the same ID.
• Candidate key helps in uniquely identifying all rows in a table. There can be multiple candidate keys per table. When designing a database, you typically choose the most efficient and suitable candidate key as the primary key.
• Foreign key is a column (or set of columns) in one table that references the primary key of another table. These establish relationships between tables, allowing users to connect data across them and ensure consistency.