Definition of unit datatable

Unit datatable would have the following keys

- primary key: 1

- name code for localization: f.i. $Nautical_mile

- Unit group: primary key of the unit group that this unit belongs to

- Unit type: to which unit type of the unit group this unit belongs to f.i. 1,2,3 (program has to check if this unit type is defined or not)

- Base unit conversion: how is this unit related to the base unit fo the group:
0 - the unit itself is a base unit f.i.: meter
1 - form of converting equation: Unit = a*Base; Base := Unit/a
2 - form of converting equation: Unit = a/Base; Base := a/Unit
3 - form of converting equation: Unit = a*Conv*Base; (Conv - variable value given by the user in a special editbox f.i. viscosity)

- a - constant for conversion