Thee Expression operator is used to write SQL expressions that define algorithms for one output parameter of the operator.
By default, the Expression operator contains one input group and one output group.
How to use it
- Drag and drop it on the mapping
- Choose the attribute for the input group
- Open it to add the attribute for the output group
- Select the output attribute
- in the attributes properties (right panel), you can add a expression in the expression properties (see the picture below)
- you can compose your expression with the Owb Expression Builder by clicking on the three point button.