Functions for Conditions and Derived Attributes¶
Derived attribute functions are used to generate new attributes in the schema of a view, applying an expression in function of the other attributes of the view, constants and/or the result of evaluating other functions. Expressions using these functions can also be used as operands in the conditions.
A function is defined as an identifier and a list of arguments that can in turn be constants, fields or other functions.
Virtual DataPort provides predefined functions. The subsections of the appendix Syntax of Condition Functions lists these functions, their syntax and examples.
- Arithmetic functions: see appendix Arithmetic Functions.
- Functions for text processing: see appendix Text Processing Functions.
- Functions for date processing: see appendix Date Processing Functions.
- Functions for processing XML values: see appendix XML Processing Functions.
- Type conversion functions: see appendix Type Conversion Functions.
- Aggregation functions: see appendix Aggregation Functions.
- Analytic functions (window functions): see appendix Analytic Functions (Window Functions).
- Other functions: see appendix Other Functions.
You can develop your own functions in Java using the Virtual DataPort API. The section Developing Custom Functions of the Developer Guide explains how to do it.