Database Relationships Explained In 5 Types
Databases define relationships between tables as 1:1, 1:N, N:1, M:N & self-referencing. Each type uses primary keys & foreign keys for data integrity. Examples include person/passport, customer/orders, employees/departments & students/courses.
Relationships in databases In databases, relationships define how tables are linked to each other. The most common types of relationships are: 1. One-to-One (1:1): Each row in Table A is linked to one and only one row in Table B, and vice versa. Example: A person and their passport. Each person has one passport, and each passport is assigned to one person. 2. One-to-Many (1:N): A single row in Table A can be associated with multiple rows in Table B, but each row in Table B is linked to only one row in Table A. Example: A customer and their orders. A customer can place mult...