Expressions can be used in a record manipulator for any of the following purposes:
Expressions are described in XML within
EXPRESSION elements, which in turn are sub-elements of a
RECORD_MANIPULATOR. The
TYPE attribute of an
EXPRESSION element describes the data type of the return
value, and the
NAME attribute of the expression describes the specific
operation an expression performs. For example, if an expression contains the
attributes
TYPE="FLOAT" and
NAME="CONST", then the expression returns a floating
point constant value. Expressions are further qualified by
EXPRNODE sub-elements that provide additional data or
instructions to the expression. Expression nodes are similar to parameters, and
expressions are similar to functions.
Oracle recommends that you perform record manipulation with a Perl
manipulator rather than with a record manipulator that uses
EXPRESSION elements. However, if you need to access and
modify dimension sources (such as a dimension adapter or dimension server) you
should still use expressions such as
DVAL PERL. The Perl manipulator does not access
dimension sources. For more information about using a Perl manipulator, see the
Developer Studio Help.
Expressions are grouped by the data type of their return value. For
example, all
FLOAT expressions return a floating-point value. There
are six categories of expressions:
FLOAT: Computes floating-point (numeric) values. These values can be constant, or can be constructed from other data contained in a record.INTEGER: Computes integer (numeric) values. These values can be constant, or can be constructed from other data contained in a record. Integer expressions can also be used in conditional expressions to modify the processing to be done on a record based on the contents of the record.DVAL: Produces dimension values. These values can be constant, or can be the result of performing a search for a dimension value within a dimension.STRING: Creates text values. These values can be constant, or can be constructed from other data contained in a record.VOID: Creates no value, but performs other work. There are VOID expressions to change property values on a record, rename properties, add dimension values, delete records, test conditions, and to evaluate arbitrary Perl code.
There are several dozen individual expressions distinguished by their
TYPE and
NAME attributes. Each expression is described in detail
in its particular help topic.
