Select rows in ADAFs

../../../../../_images/select_table_rows.svg

In the standard library there exist three nodes where rows in one or several Tables can be selected with help of defind constraint relations. The Tables in the outputs will have lesser or equal number of rows as the incoming Tables.

The rows to select are determined by constraint relations that are applied to one or many selected columns in the Table. The intersection of the results from the applied relations is used to filter the rows of the whole incoming Table.

The following operators are recognised by the node:
  • equal (==)
  • less than (<)
  • less than or equal (<=)
  • greater than (>)
  • greater than or equal (>=)
  • not equal (!=).

For two of the nodes, Select rows in Table and Select rows in Tables, the configuration GUI is used to set up a single constraint relation that can be applied to one or many columns of the incoming Table.

In the third node, Select rows in Table with Table, the constraint relations are predefined in an additional incoming Table. Three columns in this Table includes column names, comparison operators and constraint values, respectively. The comparison operators that can be used are listed above and remember to use the string expressions, as an example use equal instead of ==.

class node_select_table_rows.SelectADAFsRows

Select rows in Tables by applying a comparison relation to a number columns in the incoming Tables.

Inputs:
TableInput
: Tables

Tables with data.

Outputs:
TableOutput
: Tables

Tables with the result from the selection of rows. There will be lesser or equal number of rows compared to the incoming Tables. The number of columns is the same.

Configuration:
Columns for comparison relations :

Select columns for comparison relation.

Comparison operator:

Select comparison operator for relation.

Filter constraint :

Specify constraint value for comparison relation.

Use custom filter :

Select if one would like to use custom filter.

Custom filter :

Write a custom filter as a Python lambda function.

Preview
: button

When pressed the effects of the defined comparison relation is calculated and visualised in preview window.

Preview window :

Visualisation of the effects of the defined comparison relation.

Ref. nodes:

Select rows in Table and Select rows in Table with Table