{{ transformations:KeepRemoveColumnsAction_Remove.png}}{{ transformations:KeepRemoveColumnsAction.png}}
====== KEEP/REMOVE COLUMNS ======
Category: Transform / Basic\\

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=====Description=====
This action keeps or removes selected columns. Several columns can be kept or removed within a single action.

The action icon will depict whether this action is in "Keep" or "Remove" mode.\\

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=====Use cases=====
**Keep columns:**  Useful for keeping //only// the selected column(s) regardless of other columns being added or deleted upstream.

**Delete columns:**  Useful for removing columns that are unnecessary for downstream processing.  Removing unneeded columns early in the process lowers the computational load on the workflow/system.\\

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=====Action settings=====
====Mode options====
^ Setting  ^ Description  ^
|Keep selected columns|The chosen columns are kept and all other columns are removed from the dataset.|
|Remove selected columns|The chosen columns are removed.  You are unable to remove all columns from a dataset.|
|Fail if selected column(s) not found|Check this option //on// to stop the workflow with a //failure// if the selected column(s) is/are not in the dataset.|
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====Columns====
A list of columns found in the current dataset is presented to select which columns to keep or remove.\\

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=====Examples=====

**Example 1 (Remove columns):**  Remove the column describing the length of the river in miles.

**Source table:** The longest rivers in the world
^River  ^Length (km)  ^Length (miles)  ^Continent  ^
| Nile  |  6650|  4132|Africa  |
| Amazon  |  6400|  3976|South America  |
| Yangtze  |  6300|  3917|Asia  |
| Mississippi  |  6275|  3902|North America  |
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**Action parameters:**
>  Columns to remove: Length (miles)

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

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**Example 2 (Keep columns):**  Keep only the River and Continent columns - remove all others.

**Source table:** The longest rivers in the world
^River  ^Length (km)  ^Length (miles)  ^Continent  ^
| Nile  |  6650|  4132|Africa  |
| Amazon  |  6400|  3976|South America  |
| Yangtze  |  6300|  3917|Asia  |
| Mississippi  |  6275|  3902|North America  |
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**Action parameters:**
>  Columns to keep: River, Continent\\

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**Result table:**
^River  ^Continent  ^
| Nile  |Africa  |
| Amazon  |South America  |
| Yangtze  |Asia  |
| Mississippi  |North America  |

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====Community examples====
  * [[https://community.easymorph.com/t//1273/6|Split Excel spreadsheets into multiple spreadsheets]] ([[https://community.easymorph.com/uploads/short-url/6iWYdZJc4yAvqYMbTGZWXtVFmvL.morph|Project]]; Module: //Main//; Group: //Tab 1//; Table: //Table 1//; Action position: //2//)
  * [[https://community.easymorph.com/t//1360/2|Rounding time to the nearest minute]] ([[https://community.easymorph.com/uploads/short-url/qiQbLyXpYydJclxrArqkQzCVgr9.morph|Project]]; Module: //Main//; Group: //Tab 1//; Table: //Table 1//; Action position: //3//)
  * [[https://community.easymorph.com/t//1499/2|Data cleaning for data spread over multiple rows and columns]] ([[https://community.easymorph.com/uploads/short-url/kgmVTEHcl0CE7Yep5uzuGW1HLKc.morph|Project]]; Module: //Main//; Group: //Tab 1//; Table: //Table 1(3)//;\\ Action position: //2//)
  * [[https://community.easymorph.com/t//1649/14|Update existing data in a database table]] ([[https://community.easymorph.com/uploads/short-url/hauw3ZALjf9UqXAOP8prtLUNbxH.morph|Project]]; Module: //Main//; Group: //Tab 1//; Table: //Where clause//; Action position: //4//)
  * [[https://community.easymorph.com/t//2628/3|Matrix multiplication]] ([[https://community.easymorph.com/uploads/short-url/3fLTtB9Jd0bioRfyASiJo9m6Cqv.morph|Project]]; Module: //Main//; Group: //Group 1//; Table: //Matrix multiplication//; Action position: //7//)
  * [[https://community.easymorph.com/t//2158/5|API pagination how I create loop]] ([[https://community.easymorph.com/uploads/short-url/rQmjCeA2LXPlqzxhL5N9IoCE5CR.morph|Project]]; Module: //baseProcess//; Group: //Pull data from API//; Table: //iterationCalculation//;\\ Action position: //6//)

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=====Shortcuts=====
Fast ways to create the action:\\

**Remove columns:**
  *Right-click on the column heading and select //Remove column// from the context menu.
  *Click the drop-down arrow in the column heading and select //Remove column// from the context menu.
  *You can remove //multiple// columns by first selecting the columns to remove, then choosing //Remove (#) columns//from the context menu.

**Keep columns:**
  *Right-click on the column heading and select //Select column// from the context menu.
  *Click the drop-down arrow in the column heading and select //Select column// from the context menu.
  *You can keep //multiple// columns by first selecting the columns to keep, then choosing //Select (#) columns// from the context menu.

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=====See also=====

  * [[transformations:replacecolumn|Modify column(s)]]
  * [[transformations:rename|Rename columns]]
  * [[transformations:reorder|Reorder columns]]