cardinality

**cardinality**

In the context of databases and data modeling, **cardinality** refers to the uniqueness of data values contained in a particular column (attribute) of a database table. It describes the relationship between tables in terms of how many instances of one entity relate to instances of another. Understanding cardinality is crucial for designing efficient database schemas, optimizing queries, and ensuring data integrity. Common types of cardinality include one-to-one, one-to-many, and many-to-many relationships. This tag covers posts related to these concepts, including their applications in SQL, ER diagrams, and data structures.