Used to determine if field value is NULL.

Syntax:

function FieldIsNull(aFieldIndex : integer) : boolean;overload;
function FieldIsNull(aFieldName : string) : boolean;overload;

Description:

FieldIsNull are used to determine if field value is NULL in active record. First implementation checks field by it index. Second implementation checks field by it name.

Returns:

FieldIsNull returns true if value of requested field is NULL in current record and false if value is not NULL.