This node allows rows to be grouped by the selected columns from the input database table. Within the dialog, 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 on the "Manual Aggregation" tab are ignored even if their name matches a search pattern on the "Pattern Based Aggregation" tab or their type matches a defined type on the "Type Based Aggregation" tab. 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" tab.
The "Manual Aggregation" tab allows you to change the aggregation method of more than one column. In order to do so select the columns to change, open the context menu with a right mouse click and select the aggregation method to use.
In the "Pattern Based Aggregation" tab 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 on the "Manual Aggregation" tab are considered.
The "Type Based Aggregation" tab 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 tabs e.g. group, column based and pattern based are considered. The data type list to choose from contains basic types e.g String, Double, etc. and all data types the current input table contains.
A detailed description of the available aggregation methods can be found on the 'Description' tab in the node dialog.
You want to see the source code for this node? Click the following button and we’ll use our super-powers to find it for you.
A zipped version of the software site can be downloaded here.
Do you have feedback, questions, comments about NodePit, want to support this platform, or want your own nodes or workflows listed here as well? Do you think, the search results could be improved or something is missing? Then please get in touch! Alternatively, you can send us an email to email@example.com, follow @NodePit on Twitter, or chat on Gitter!
Please note that this is only about NodePit. We do not provide general support for KNIME — please use the KNIME forums instead.