Applies To
OValue
Description
This method returns TRUE if value of the variable is NULL.
Usage
oboolean IsNull(void) const
Remarks
NULL is a possible value for Oracle database fields. This database NULL is
different from a C++ NULL. Database NULLs mean "no value set".
An OValue can contain a value of NULL. This routine tells you whether the OValue contains a NULL. Note that if you cast a NULL to (for example) an integer,
you get a result of 0.
Return Value
TRUE if the value is NULL; FALSE otherwise.
Example
NULL and not-NULL values in an OValue variable:
// construct an OValue with a value of 5
OValue val(5);
// is that NULL?
oboolean isnull = val.IsNull();
// isnull is FALSE
// make it NULL
val.Clear();
isnull = val.IsNull();
// now isnull is TRUE
