1. ADABAS provides a rich choice of declarative integrity rules, thus simplifying the programming of applications.
2. A key consisting of one or more columns can be defined for each table. ADABAS ensures that keys in a table are unique. A key can be composed of columns of different data types.
3. In addition, uniqueness can be enforced for the values of other columns or column combinations (UNIQUE definition for 'alternate keys').
4. For single columns, values other than the NULL value can be enforced by specifying NOT NULL.
5. For each column, a value can be predefined (DEFAULT definition).
6. The specification of declarative integrity rules with regard to one table is possible.
7. Declarations of referential integrity constraints for delete and existence conditions between the rows of two tables can be made as well.
8. Complex integrity rules requiring access to more tables can be formulated using triggers or DB procedures.