Oracle® OLAP DML Reference 10g Release 2 (10.2) Part Number B14346-03 |
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Within an OLAP DML program, the VARIABLE command declares a local variable or valueset for use within that program. A local variable cannot have any dimensions and exists only while the program is running.
VARIABLE name {datatype|dimension|VALUESET dim}
The name for the local variable or valueset. When you use the same name as an existing analytic workspace object, the local variable or valueset takes precedence over the analytic workspace object. After you assign a value to the variable or valueset, its value will be available within the program where the VARIABLE statement occurs. You name a variable or valueset according to the rules for naming analytic workspace objects (see the DEFINE command).
The data type of the variable, which indicates the kind of data to be stored. You can specify any of the data types that are listed and described in the DEFINE VARIABLE entry. Also, when you want to the program to be able to receive an argument without converting it to a specific data type, you can also specify WORKSHEET
for the data type.
Indicates that name is a relation variable, which holds a single value of the specified dimension. The variable can hold a value of the dimension or a position (INTEGER
) of the specified dimension. Assigning a value that does not currently exist in the dimension causes an error.
Indicates that name is a valueset. The dim argument is the name of the dimension for which the valueset holds values.
Persistence of a Local Variable
A local variable or valueset exists only while the program that specified it is running. When the program terminates, the variable or valueset ceases to exist and its value is lost. A program can terminate when a RETURN statement, SIGNAL statement, or the last line of the program executes. When the program calls another program, the original program is temporarily suspended and the variable or valueset does exist when the called program ends and control returns to the original program. A program that calls itself recursively has separate local variable or valuesets for each running copy of the program.
Declarations at the Start Of A Program
You must specify all your local variables or valuesets at the beginning of a program, before any executable statements.
Initial Value of a Local Variable or Valueset
The value of a local variable or valueset is initially NA
.
Duplicating the Name of an Analytic Workspace Object
When you give a local variable or valueset the same name as an analytic workspace object, Oracle OLAP assumes you are referring to the local variable or valueset within the program. The analytic workspace object has priority only when the statement requires an analytic workspace object as an argument.
Although the OBJ and EXISTS functions expect an analytic workspace object as an argument, you can use a local text variable or valueset to specify the name of an object.
You cannot use local variables or valuesets in a formula or model.
In a program, you can use an EXPORT (to EIF) statement to store the value of a local variable or valueset in an EIF file. You must use the AS keyword to give the variable or valueset an analytic workspace object name. The name can be the same as the name of the local variable or valueset. When you use IMPORT (from EIF) to retrieve the value, it is stored as an analytic workspace object. You cannot import the value into a local variable or valueset.
Example 26-33 Saving a File Unit Number
Suppose you want to write a program to read data from an input file with Data Reader statements. First you need to open the file and save the value of the file unit number assigned to it. At the beginning of the program you can specify a local variable called unit
to hold the file unit number.
DEFINE read.file PROGRAM LD Read monthly sales data into the analytic workspace PROGRAM VARIABLE unit INTEGER TRAP ON error unit = FILEOPEN('sales.data' READ) ...
Example 26-34 Returning a Dimension Value from a Program
Suppose you want to write a program that analyzes sales for various districts and returns the name of the district in which sales were highest. For the purpose of analysis, the program defines a local variable to hold the district name. When the program ends, it returns the value of the local variable.
DEFINE highsales PROGRAM PROGRAM VARIABLE districtname district ... "(statements that find the highest district) RETURN districtname END