Handling NULL Values 
Use
SQL NULL values are special values that indicate that a database field contains no information.
Features
To define a database column whose value can be null, you must leave the Not Null property unchecked when creating the database table in the Java Dictionary.
To represent a database NULLvalue, SQLJ does not use indicator variables as known from other embedded SQL languages (for example, Native SQL for ABAP). Instead, it uses the null value of the Java wrapper classes of the primitive Java types.
If you try to fetch
a NULL value to a primitive Java type, you get an
sqlj.runtime.SQLNullException. To avoid this situation, the SQLJ
translator issues a warning if a primitive type is used as the fetch target
and the matching result set column may contain null values.
See also: