The DB GroupBy node allows rows to be grouped by the selected columns from the input DB Data connection. An SQL GROUP BY clause is interactively created by selecting the columns to group by and the columns to aggregate.
The columns to aggregate can be either defined by selecting the columns directly, by name based on a search pattern or based on the data type. Input columns are handled in this order and only considered once e.g. columns that are added directly in the "Manual Aggregation" section are ignored even if their name matches a search pattern in the "Pattern Based Aggregation" section or their type matches a defined type in the "Type Based Aggregation" section. The same holds for columns that are added based on a search pattern. They are ignored even if they match a criterion that has been defined in the "Type Based Aggregation" section.
In the "Pattern Based Aggregation" section you can assign aggregation methods to columns based on a search pattern. The pattern can be either a string with wildcards or a regular expression . Columns where the name matches the pattern but where the data type is not compatible with the selected aggregation method are ignored. Only columns that have not been selected as group column or that have not been selected as aggregation column in the "Manual Aggregation" section are considered.
The "Type Based Aggregation" section allows to select an aggregation method for all columns of a certain data type e.g. to compute the mean for all decimal columns (DoubleCell). Only columns that have not been handled by the other sections e.g. group, column based and pattern based are considered. The data type list to choose from contains the types of the input table and all registered data types.