User's Guide
PART 2. Relational Database Concepts
This chapter describes the facilities in Adaptive Server Anywhere for ensuring that the data in your database is valid and reliable. Building integrity constraints right into the database is the surest way to make sure your data stays in good shape.
Several types of integrity constraints can be enforced. You can ensure individual entries are correct by imposing constraints and CHECK conditions on tables and columns. Setting column properties by choosing an appropriate data type or setting special default values assists this task.
The SQL statements in this chapter use the CREATE TABLE statement and ALTER TABLE statement, basic forms of which were introduced in Working with Database Objects.
Data integrity overview
Using column defaults
Using table and column constraints
Enforcing entity and referential integrity
Integrity rules in the system tables