Database Constraints

Review on Database Constraints

“Database Constraints”

are rules applied to columns or tables in a database that enforce specific conditions on the data stored within them. They are essential for maintaining data integrity, accuracy, and reliability by restricting the types of data that can be entered or modified.

“Primary Key Constraint”

is a constraint that uniquely identifies each record in a database table, ensuring that no two rows have the same value in the specified column(s). It enforces entity integrity by preventing null values and duplicates.

“Foreign Key Constraint”

is a constraint that establishes a relationship between two tables by ensuring that the value in one table matches a value in another, thereby enforcing referential integrity.

“Check Constraint”

is a constraint that allows you to specify a condition that must be met for the values in a column. It ensures that the data entered into the column adheres to a specific rule or range.