Defining CHECK Constraints

From InterBase
Jump to: navigation, search

Go Up to Developing a Set of Rules (Designing Databases)


Along with preventing the duplication of values using UNIQUE and PRIMARY KEY constraints, you can specify another type of data entry validation. A CHECK constraint places a condition or requirement on the data values in a column at the time the data is entered. The CHECK constraint enforces a search condition that must be true in order to insert into or update the table or column.

Advance To: