{{ transformations:ExpressionFilterAction.png}}
====== FILTER BY CONDITION======
Category: Transform / Filters\\

\\ 
=====Description=====
This action calculates an [[syntax:start|expression]] for every row (without adding a new column) 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.\\

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.\\

\\
=====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 ^
|Expression|Enter 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=====
Examples of valid conditions:
<code>
[Amount]=0
  
[Length] * [Width] * [Height] <= 1000
  
contains([City], 'York')
  
not isempty([Email])

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


\\ 
=====Examples=====
**Example:** Find all rivers that are longer than 6000 km.\\

**Source table:** The longest rivers in the world
^River  ^Length (km)  ^Continent  ^
| Nile  |  6650| Africa  |
| Amazon  |  6400| South America  |
| Yangtze  |  6300| Asia  |
| Mississippi  |  6275| North America  |
| Yenisei  |  5539| Asia  |
| Yellow River  |  5464| Asia  |
| Ob  |  5410| Asia|
| Paraná  |  4880| South America  |
\\ 
**Action parameters:**
> Expression: [Length (km)] > 6000

\\ 
**Result table:**
^River  ^Length (km)  ^Continent  ^
| Nile  |  6650| Africa  |
| Amazon  |  6400| South America  |
| Yangtze  |  6300| Asia  |
| Mississippi  |  6275| North America  |

\\ 
====Community examples====
  * [[https://community.easymorph.com/t//675/5|Compare two Excel sheets with EasyMorph]] ([[https://community.easymorph.com/uploads/short-url/xQLWtAogCqcMrglyfXLKmrAF7aR.morph|Project]]; Module: //Main//; Group: //Main//; Table: //Result//; Action position: //3//)
  * [[https://community.easymorph.com/t//1625/4|Create a new table with columns based on row values]] ([[https://community.easymorph.com/uploads/short-url/4oGLUNDHrUfB971H80ciuOAtOTG.morph|Project]]; Module: //Module 1//; Group: //Tab 1//; Table: //Table 1//; Action position: //2//)
  * [[https://community.easymorph.com/t//1649/4|Update existing data in a database table]] ([[https://community.easymorph.com/uploads/short-url/yB6WDyNxKmlLT3bbm6mTr76C4Ri.morph|Project]]; Module: //Main//; Group: //Tab 1//; Table: //Where clause//; Action position: //2//)
  * [[https://community.easymorph.com/t//1766/1|Load only workbooks with given number of sheets]] ([[https://community.easymorph.com/uploads/short-url/AbWPlfPVBecqgZUBVTYlljwb9NO.morph|Project]]; Module: //Main//; Group: //Tab 1//; Table: //Get file names to load//;\\ Action position: //5//)
  * [[https://community.easymorph.com/t//2041/6|Join 2 tables with multi criterions equal and not equals in where]] ([[https://community.easymorph.com/uploads/short-url/kNkqMsDYMJjzjiN4C5g8O4g3YlA.morph|Project]]; Module: //Main//; Group: //Tab 1//; Table: //Join//; Action position: //3//)

\\ 
=====See also=====
  * [[transformations:selectionfilter|Filter]]
  * [[transformations:searchfilter|Filter by search]]
  * [[transformations:filterbytype|Filter by type]]
  * [[syntax:start|Expressions:  Expression syntax]]