User Tools

Site Tools


transformations:filter

FILTER BY CONDITION

Category: Transform / Filters


Description

This action calculates an expression for every row and keeps only rows where this expression is TRUE. All other rows are removed. If no rows satisfy the condition then all rows are removed.


Use cases

  • Create subsets of a dataset based on values across multiple columns.
  • Clean a dataset by removing records that don't meet certain criteria, or evaluate to a certain value.


Action settings

Setting Description
ExpressionEnter an expression that evaluates to a boolean TRUE/FALSE result. The expression will be applied to each
record and remove records that do not meet the criteria (evaluate to FALSE).


Remarks

The expression must be a valid condition – it must return either TRUE or FALSE for any row in the table. If it results in a non-boolean value (i.e. not TRUE or FALSE) for at least one row it will cause a project execution error.

Examples of valid conditions:

[Amount]=0
  
[Length] * [Width] * [Height] <= 1000
  
contains([City], 'York')
  
not isempty([Email])

[Date] >= #2024-02-01 and [Date] <= #2024-02-29


Examples

Example #1

Find all mountains that are taller than 8600 m.

Before (source table)

Rank Mountain Height (m)
1Mount Everest 8848.86
2K2 8611
3Kangchenjunga 8586
4Lhotse 8516
5Makalu 8485
6Cho Oyu 8188

After (result table)

Rank Mountain Height (m)
1Mount Everest 8848.86
2K2 8611

Action parameters

Expression: [Height (m)] > 8600


Community examples


See also

transformations/filter.txt · Last modified: 2025/01/20 00:57 by craigt

Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki