ASA SQL User's Guide
  Designing Your Database
    Designing the database table properties

Choosing data types for columns

Available data types in Adaptive Server Anywhere include the following:

• Integer data types

• Decimal data types

• Floating-point data types

• Character data types

• Binary data types

• Date/time data types

• Domains (user-defined data types)

• Java class data types

For more information about data types, see SQL Data Types.

The long binary data type can be used to store information such as images (for instance, stored as bitmaps) or word-processing documents in a database. These types of information are commonly called binary large objects, or BLOBS.

For more information about each data type, see SQL Data Types.

NULL and NOT NULL 

If the column value is mandatory for a record, you define the column as being NOT NULL. Otherwise, the column is allowed to contain the NULL value, which represents no value. The default in SQL is to allow NULL values, but you should explicitly declare columns NOT NULL unless there is a good reason to allow NULL values.

For more information about the NULL value, see NULL value. For information on its use in comparisons, see Search conditions.