Variables

Variables are the paramters of a query that you define in the query designer and that are filled with values when you execute the query or web application.Variables are reusuable objects. This means that when you define a variable for a query in the query designer, this variable can be used in all other queries. Variables are not dependent on the Infoproviders, but only on the Infoobject. A Variable that you define for an info object is available in all infoproviders that uses this infoobject.
USE: Variables enables you to customize queries flexibly (parametrize the query) possible. If we use variables in query designer do not select any fixed characteristic values, hierarchies, hierarchy nodes, texts, formula elements.
Instead, setup variables as placeholders. These are then filled with the values when the query is running.
We can use one query definition as the foundation for many different queries if we use variables.
There are two tools in the query designer for designing and changing variables:
1.Variable Wizard    and     2. Variable Editor
Variable Wizard take you step by step through the process of defining a variable. Each individual step is context sensitive and is adjusted according to the combination of variable and processing types used. This means that the variable wizard only offers the selection options that are permitted for that combination of variable and processing type i.e., variable wizard are used to create or define the variables.
2.Variable Editor: The variable Editor dialogue box offers all of the selection options for changing and existing variable. The individual fields in the dialogue box shows effected in the variable. We can change the setting. If you want to make the changes using a step by step process with an explanatory text we can jump to the variable wizard .

Types of Variables:
The type of variable being used. This determines the object that the variable represents as a placeholder or a concrete value.
There are different types of variables depending on the both for which want define variables. There are 5 types of variables.
1. Characteristic Value Variable: These represent characteristic values and can be used wherever characteristic values are used.
2. Hierarchy Variable: These represent hierarchies and can be used wherever hierarchies can be selected.
3. Hierarchies Node Variable; These represent a node in a hierarchy and can be used wherever hierarchy nodes are used.
4. Text Variable: These represent a texts and can be used in descriptions of queries calculated keyfigures and structural components.
5.Formula Variables; These represent numerical variable and can be used in formulas. In addition numerical variables are used for selecting exceptions and conditions and we can also use formula variables here. We can use a formula variable for interest rate in order to process the current interest rate, after you have executed the query or web application.
Variable Processing Types;
The processing type of a variable determines how a variable is filled with a value for the runtime of the query or web application. There are 5 types of variable processing types. They are
1. Manual Entry/Default value or User Entry/Default value:
2. Replacement Path
3.Customer Exit
4. SAP Exit
5.Authorization.
Depending on the type of variable used the possible processing types are offered in the variable wizard.