- 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.
- LocalVariable
contains a value in a procedure.
- ProcedureParameter
contains a value that is passed into or out of a
procedure.
- Built-inVariable
is one of the following built-in variables used
for error handling:
The first six of these have the same meaning that they have
as fields in the SQLCA in application programs. Note that in procedures,
sqlerrd2 returns the number of rows processed for all host languages.
However, in application programs, sqlerrd3 is used in COBOL, Fortran,
and Pascal, while sqlerr2 is used in C. ::activexact indicates whether
a transaction is in progress or not. For additional information,
refer to the application programming guides and to Chapter 4 “Constraints, Procedures, and Rules”
- AddMonthsFunction
returns a value that represents a DATE or DATETIME value
with a certain number of months added to it.
- AggregateFunction
is a computed value; aggregate functions are defined
in this chapter.
- Constant
is a specific value; constants are defined later
in this chapter.
- ConversionFunction
returns a value that is a conversion of a date/time
data type into an INTEGER or CHAR value, or from a CHAR value.
- CurrentFunction
returns a value that represents the current DATE,
TIME, or DATETIME.
- LongColumnFunction
returns information from a long column descriptor.
- StringFunction
returns a partial value or attribute of string data.
- TIDFunction
returns the database address of a row (or rows for
a BULK SELECT) of a table or an updatable view. You cannot use mathematical
operators with this function except to compare it to a value, host
variable, or dynamic parameter (using =, or <>)
.
- (Expression)
is one or more of the above primaries, enclosed
in parentheses.
- NOT
reverses the value of the predicate that follows
it.
