# Keep or drop columns Shape / columns A variant of [Choose and rename columns](https://meridian.online/operations/choose-and-rename-columns). Keep the named columns and drop the rest, or drop the named columns and keep the rest. Page: ## Status Runs as a SQL step. arcform carries it as a `sql:` step today. ## The DuckDB step keep named columns, or drop them and keep the rest It reads the `orders` table the proofs share. Create it first: ```sql CREATE TABLE orders AS SELECT * FROM (VALUES (1, 'Alice Ng', 'north', DATE '2026-01-03', 120.00, 'widget', 'a|b', '{"channel":"web","items":[1,2]}'), (2, 'alice ng', 'north', DATE '2026-01-05', 80.50, 'gadget', 'b', '{"channel":"shop","items":[3]}'), (3, 'Bob Okafor', 'south', DATE '2026-01-05', 300.00, 'widget', 'a|c', '{"channel":"web","items":[4,5,6]}'), (4, 'Carla Díaz', 'east', DATE '2026-01-09', NULL, 'gizmo', NULL, '{"channel":"web","items":[]}'), (5, 'Bob Okafor', 'south', DATE '2026-01-12', 45.25, 'gadget', 'c', '{"channel":"phone","items":[7]}'), (6, 'Dev Patel', 'west', DATE '2026-01-12', 510.00, 'widget', 'a', '{"channel":"web","items":[8,9]}'), (7, 'Carla Diaz', 'east', DATE '2026-01-20', 99.99, 'gizmo', 'b|c', '{"channel":"shop","items":[10]}'), (8, 'Dev Patel', 'west', DATE '2026-02-02', 510.00, 'widget', 'a', '{"channel":"web","items":[8,9]}'), (9, 'Eve Larsen', NULL, DATE '2026-02-03', 15.00, 'gadget', NULL, '{"channel":"web","items":[11]}'), (10, 'Alice Ng', 'north', DATE '2026-02-10', 220.00, 'gizmo', 'a|b|c', '{"channel":"phone","items":[12,13]}') ) t(order_id, customer, region, order_date, amount, product, tags, meta); ``` Then run the statement: ```sql CREATE TEMP TABLE kept AS SELECT order_id, customer, amount FROM orders; CREATE TEMP TABLE dropped AS SELECT * EXCLUDE (meta, tags, region, product) FROM orders; SELECT * FROM kept; SELECT * FROM dropped; SELECT CASE WHEN ((SELECT list(column_name) FROM (DESCRIBE kept)) = ['order_id', 'customer', 'amount'] AND (SELECT list(column_name) FROM (DESCRIBE dropped)) = ['order_id', 'customer', 'order_date', 'amount'] AND (SELECT count(*) FROM kept) = 10) THEN 'as expected' ELSE error('keeping three columns and dropping four did not leave the three named and the four others') END AS verdict; ``` It needs nothing installed beyond DuckDB itself. ## What other tools call it Meridian's classification; an independent blind rating agreed on 95.7% of 324 rows (variant, version 3). - Apache DataFusion: [`Wildcards (EXCLUDE / EXCEPT)`](https://datafusion.apache.org/user-guide/sql/select.html) (read 2026-09-27) - Apache DataFusion: [`drop_columns`](https://docs.rs/datafusion/latest/datafusion/dataframe/struct.DataFrame.html) (read 2026-09-27) - Apache DataFusion: [`select_columns`](https://docs.rs/datafusion/latest/datafusion/dataframe/struct.DataFrame.html) (read 2026-09-27) - Duckle: [`Drop Columns`](https://github.com/slothflowlabs/duckle/blob/f85f8960edfb6efbf4cb89d58a7b32e16df0e867/website/docs/components.html) (read 2026-09-25) - Duckle: [`Project / Select`](https://github.com/slothflowlabs/duckle/blob/f85f8960edfb6efbf4cb89d58a7b32e16df0e867/website/docs/components.html) (read 2026-09-25) - EasyMorph: [`Keep/remove columns`](https://help.easymorph.com/doku.php?id=transformations:keepremovecolumns) (read 2026-09-27) - AWS Glue: [`DropFields`](https://docs.aws.amazon.com/glue/latest/dg/transforms-configure-drop-fields.html) (read 2026-09-27) - AWS Glue: [`DropFields`](https://docs.aws.amazon.com/glue/latest/dg/aws-glue-api-crawler-pyspark-transforms-DropFields.html) (read 2026-09-27) - AWS Glue: [`SelectFields`](https://docs.aws.amazon.com/glue/latest/dg/transforms-configure-select-fields.html) (read 2026-09-27) - AWS Glue: [`SelectFields`](https://docs.aws.amazon.com/glue/latest/dg/aws-glue-api-crawler-pyspark-transforms-SelectFields.html) (read 2026-09-27) - Ibis: [`DropColumns`](https://github.com/ibis-project/ibis/blob/05d2b293344e86cb41c1a426071734f7e270335a/ibis/expr/operations/relations.py) (read 2026-09-27) - KNIME Analytics Platform: [`Column Filter`](https://api.hub.knime.com/nodes/*DOkyMaii62U05xZ1?details=full) (read 2026-09-27) - KNIME Analytics Platform: [`Column Filter (PMML)`](https://api.hub.knime.com/nodes/*1QQFxIzeu9KVOVPZ?details=full) (read 2026-09-27) - KNIME Analytics Platform: [`DB Column Filter`](https://api.hub.knime.com/nodes/*uZeXvabxqmm1IjdI?details=full) (read 2026-09-27) - Apache NiFi: [`FilterAttribute`](https://nifi.apache.org/components/org.apache.nifi.processors.standard.FilterAttribute/) (read 2026-09-27) - Apache NiFi: [`RemoveRecordField`](https://nifi.apache.org/components/org.apache.nifi.processors.standard.RemoveRecordField/) (read 2026-09-27) - OpenRefine: [`Remove this column`](https://openrefine.org/docs/manual/columnediting#renaming-removing-and-moving) (read 2026-09-27) - Polars: [`DataFrame.drop`](https://docs.pola.rs/api/python/stable/reference/dataframe/modify_select.html) (read 2026-09-27) - Polars: [`DataFrame.drop_in_place`](https://docs.pola.rs/api/python/stable/reference/dataframe/modify_select.html) (read 2026-09-27) - Polars: [`Expr.exclude`](https://docs.pola.rs/api/python/stable/reference/expressions/columns.html) (read 2026-09-27) - Power Query M: [`Table.Column`](https://learn.microsoft.com/en-us/powerquery-m/table-functions#column-operations) (read 2026-09-27) - Power Query M: [`Table.RemoveColumns`](https://learn.microsoft.com/en-us/powerquery-m/table-functions#column-operations) (read 2026-09-27) - Power Query M: [`Table.SelectColumns`](https://learn.microsoft.com/en-us/powerquery-m/table-functions#column-operations) (read 2026-09-27) - RapidMiner Studio: [`Select Attributes`](https://docs.rapidminer.com/latest/studio/operators/blending/attributes/selection/select_attributes.html) (read 2026-09-27) - RapidMiner Studio: [`Select Attributes (In Database)`](https://docs.rapidminer.com/latest/studio/operators/extensions/In-Database%20Processing/indb_blending/indb_select.html) (read 2026-09-27) - RapidMiner Studio: [`Select by Random`](https://docs.rapidminer.com/latest/studio/operators/blending/attributes/selection/select_by_random.html) (read 2026-09-27) - Apache SeaTunnel: [`Filter`](https://seatunnel.apache.org/docs/2.3.13/transforms/filter) (read 2026-09-27) - Tableau Prep: [`Hide Field`](https://help.tableau.com/current/prep/en-us/prep_filter.htm) (read 2026-09-27) - Tableau Prep: [`Keep Only Field`](https://help.tableau.com/current/prep/en-us/prep_clean.htm) (read 2026-09-27) - Tableau Prep: [`Remove Field`](https://help.tableau.com/current/prep/en-us/prep_clean.htm) (read 2026-09-27) - Trifacta: [`Delete columns`](https://help.alteryx.com/aac/en/trifacta-classic/reference/transformation-reference.html) (read 2026-09-27) - Trifacta: [`Drop Transform`](https://help.alteryx.com/aac/en/trifacta-classic/wrangle-language/language-appendices/transforms.html) (read 2026-09-27) - Trifacta: [`Select`](https://help.alteryx.com/aac/en/trifacta-classic/reference/transformation-reference.html) (read 2026-09-27) - VisiData: [`hide-col`](https://github.com/saulpw/visidata/blob/7609212ec2febafa9caba7183cbebfaf49627909/visidata/features/layout.py#L79) (read 2026-09-23) - VisiData: [`hide-selected`](https://github.com/saulpw/visidata/blob/7609212ec2febafa9caba7183cbebfaf49627909/visidata/metasheets.py#L141) (read 2026-09-23) - VisiData: [`unhide-cols`](https://github.com/saulpw/visidata/blob/7609212ec2febafa9caba7183cbebfaf49627909/visidata/features/layout.py#L83) (read 2026-09-23)