Indicator Variables and their Usage

Indicator variables are optional variables used to handle null values. Each indicator variable is associated with one host variable. Indicator variables should be of type short or SMALLINT.

• Programs use indicator variables to insert null values into the database. (There are other techniques to do this; see "Inserting NULL Values" and "Using NULL Values in Expressions" for more details.)
• SQL uses indicator variables to indicate that it returned a null value from the database, or that it returned a value that it was forced to truncate. (Again, there are other ways to check for null values; see "Using NULL Values in the WHERE Clause" for more details.)