OLAP_EXPRESSION_TEXT
is a SQL function that dynamically executes a single-row character function in an analytic workspace and returns the results.
See Also:
Chapter 7, "OLAP_EXPRESSION"This chapter includes the following topics:
OLAP_EXPRESSION_TEXT
acts as a single-row character function within the context of a SELECT FROM OLAP_TABLE
statement. You can specify OLAP_EXPRESSION_TEXT
in the same way you specify other Oracle single-row functions, notably in the select list and WHERE
and ORDER BY
clauses.
Single-row functions return a single result row for every row of a queried table or view. Oracle supports a number of predefined single-row functions, for example COS
, LOG
, and ROUND
which return numeric data, and UPPER
and LOWER
which return character data. For more information on single-row functions, refer to the Oracle Database SQL Reference.
The OLAP single-row functions, OLAP_EXPRESSION
and its variants for text, date, and boolean data, return the result of an OLAP DML expression that you specify. The OLAP DML supports a rich syntax for specifying computations ranging from simple arithmetic expressions to statistical, financial, and time-series operations.
You can use OLAP_EXPRESSION_TEXT
to dynamically calculate any valid text expression within an analytic workspace and retrieve its results. For more information on text expressions in the OLAP DML, search for "text expression" in the Oracle OLAP DML Reference.
OLAP_TABLE
uses a limit map to present the multidimensional data from an analytic workspace in tabular form. The limit map specifies the columns of the logical table. When an OLAP_EXPRESSION_TEXT
function is specified in the select list of the query, OLAP_TABLE
generates an additional column for the results of the function.
To use OLAP_EXPRESSION_TEXT
, you must specify a ROW2CELL
clause in the limit map used by OLAP_TABLE
. ROW2CELL
identifies a RAW
column that OLAP_TABLE
populates with information used by the OLAP single-row functions.
The OLAP_EXPRESSION_TEXT
function dynamically executes an OLAP DML text expression within the context of an OLAP_TABLE
function.
OLAP_EXPRESSION_TEXT( r2c IN RAW(32), text_expression IN VARCHAR2) RETURN NUMBER;
Table 10-1 OLAP_EXPRESSION_TEXT Function Parameters
Parameter | Description |
---|---|
|
The name of a column populated by a
|
|
A text expression in the analytic workspace. Search for "text expression" in the Oracle OLAP DML Reference. See also "Guidelines for Using Quotation Marks in OLAP DML Commands". |
An evaluation of text_expression for each row of the table object returned by the OLAP_TABLE
function.
OLAP_EXPRESSION_TEXT
returns character data. To return numeric, boolean, or date data, use the OLAP_EXPRESSION
, OLAP_EXPRESSION_BOOL
, or OLAP_EXPRESSION_DATE
functions.
Refer to "OLAP_EXPRESSION Examples" and "OLAP_EXPRESSION_BOOL Example" for examples of OLAP single-row functions.