Simple and Smart Lookup Tables

This section introduces lookup tables and includes the following topics:

Understanding Lookup Tables

A lookup table is a special modification of the decision table which simultaneously contains vertical and horizontal conditions and returns value on crossroads of matching condition values.

That means condition values can appear either on the left of the lookup table or on the top of it. The values on the left are called vertical and values on the top are called horizontal. Any lookup table must have at least one vertical and at least one horizontal value.

A lookup table example

Lookup Tables Implementation Details

This section describes internal OpenL Tablets logic.

At first, the table goes through parsing and validation.

  • On parsing, all parts of the table, such as header, columns headers, vertical conditions, horizontal conditions, return column, and their values, are extracted.
  • On validation, OpenL checks if the table structure is proper.

Then OpenL Tablets transforms a lookup table into a regular decision table internally and processes it as a regular decision table.