ALLBASE/SQL Reference Manual (36216-90216)

Chapter 9 275
Search Conditions
NULL Predicate
NULL Predicate
A NULL predicate determines whether a primary has the value NULL. The predicate
evaluates to true if the primary is NULL. If the NOT option is used, the predicate
evaluates to true if the primary is not NULL.
Scope
SQL Data Manipulation Statements
SQL Syntax
{ColumnName
: HostVariable [[INDICATOR]: IndicatorVariable ]
?
:LocalVariable
:ProcedureParameter
:: Built-inVariable
AddMonthsFunction
AggregateFunction
Constant
DateTimeFunction
CurrentFunction
LongColumnFunction
StringFunction
CASTFunction
TIDFunction
(Expression) } IS [NOT] NULL
Parameters
ColumnName is the name of a column from which a value is to be taken;
column names are defined in Chapter 6 , “Names.”.
HostVariable contains a value in an application program being input to
the expression.
IndicatorVariable names an indicator variable, whose value
determines whether the associated host variable contains
a NULL value:
> = 0
the value is not NULL
< 0
the value is NULL (The value in the host variable will be
ignored.)
? is a place holder for a dynamic parameter in a prepared
SQL statement in an application program. The value of
the dynamic parameter is supplied at run time.