User's Guide Part III. Using SQL AnywhereThis chapter describes SQL Anywhere's facilities 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 in SQL Anywhere databases. 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 the chapter "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