By the help of the variable we can create a variable during running (when starting the query) to be specified by the user.

Setting possibilities:
| • | Name: this will be the name of the variable, as reference in the expression (should be unique in the given group). |
| • | Number type: we can give here if we want to use an integral or a floating point number |
| • | Number of decimals: in case of floating number presentation we can give the maximum number of decimals |
| • | Minimum value: the minimum value which can be given by the user |
| • | Maximum value: the maximum value which can be given by the user |