Indicator variables are C variables that hold supplementary information about a particular host variable. You can use a host variable when fetching or putting data. Use indicator variables to handle NULL values.

An indicator variable is a host variable of type a_sql_len that is placed immediately following a regular host variable in a SQL statement. To detect or specify a NULL value, place the indicator variable immediately following a regular host variable in a SQL statement.

 Example

EXEC SQL INSERT INTO Employee
   VALUES (:employee_number, :employee_name,
   :employee_initials, :employee_phone:ind_phone );

 Indicator variable values