Concepts → Expression
An expression returns a scalar or an array of values of a specific data type. An expression can consist of built-in functions, built-in system variables, and other referenceable objects valid for the expression context.
You can create complex expressions with the Formula Builder using any of the following as allowed by the expression context:
- Built-in function
- Built-in system variable
- Built-in system date variable
- Business schema view column
- Business schema view formula column
- External session variable
- Global variable
- Incorta Table column
- Incorta Table formula column
- Incorta View column
- Incorta View formula column
- Internal session variable
- Presentation variable
- Physical schema table column
- Physical schema table formula column
The expression context determines the validation rules for the expression itself and the limitations of the expression.
For example, the expression context of a physical schema table formula column allows only for referenceable objects within the scope of physical schemas and the Loader Service. For this reason, when creating a formula column in the Table Editor, it is not possible to reference a business schema view column in the formula column expression as a business schema view column is a runtime reference to an in-memory object in the Analytics Service.
An example of a contextual limitation is a Load Filter expression. Incorta only allows physical schema table columns as in a SQL wildcard query.
In order to reference a column or variable in an expression, you must have View access rights to the grandparent object (schema or business schema) or the variable.
There are several types of expressions that you can create using the Formula Builder: