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transformations:filterbytype

FILTER BY TYPE

Category: Transform / Filters


Description

This action filters values depending on their data type. Filtering can be applied to several columns at once, as well as multiple data types.


Use cases

Filtering by type helps detect data quality issues by ensuring that columns in the exported dataset are strongly typed (i.e. all values in a column are of the same type). This might be required before exporting into a target system with strongly typed fields, such as a relational database or a Tableau data extract.


Action settings

Setting Description
Filter modeSelect whether to keep or remove values of the types specified. Options: Keep only values of selected type(s) or
Remove values of the selected types.
Data typesSelect the data types to be filtered by. Options: Text, Number, Boolean, Error, and Empty (null).
Columns to checkSelect whether to check the entire table or specific columns. Options: Entire table or Particular columns (and
select the columns to check).


Remarks

In cases where no values match the search string:

  • If Keep only values… was selected, the result will be an empty dataset.
  • If Remove values… was selected, the result will be the full dataset (no rows removed).


Examples

Objective: Filter out all non-numberic values in the "Length (km)" column.

Source table: The longest rivers in the world

River Length (km) Continent
Nile 6650 Africa
Amazon 6400 South America
Yangtze N/A Asia
Mississippi 6275 North America
Yenisei 5539 Asia
Yellow River 5464 Asia
Ob 5410 Asia
Paraná South America


Action parameters:

Filter mode is "Keep only values of selected type(s)"
Data types: "Number" selected
Columns to check; Particiular columns: "Length (km)"


Result:

River Length (km) Continent
Nile 6650 Africa
Amazon 6400 South America
Mississippi 6275 North America
Yenisei 5539 Asia
Yellow River 5464 Asia
Ob 5410 Asia


See also

transformations/filterbytype.txt · Last modified: 2021/04/28 14:56 by dmitry