# Write a CSV or delimited file Publish / file write CSV, TSV, fixed-width Page: ## Status Runs as a SQL step. arcform carries it as a `sql:` step today. ## The DuckDB step write CSV 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 COPY (SELECT * FROM orders) TO '/out.csv' (HEADER, DELIMITER ','); CREATE TEMP TABLE result AS SELECT count(*) AS n, sum(amount) AS total FROM read_csv('/out.csv'); SELECT * FROM result; SELECT CASE WHEN ((SELECT n = 10 AND total = 1900.74 FROM result)) THEN 'as expected' ELSE error('the CSV written does not read back as 10 rows totalling 1900.74') END AS verdict; ``` Replace `` with a directory of your own that you can write to before running the statement. The statement writes `out.csv` itself, in ``. It needs nothing installed beyond DuckDB itself. ## Variants - Write a delimited text file: Write rows as text with a separator between fields, such as commas, tabs or pipes. - Write a fixed-width file: Write rows as text where each field takes a set number of characters, padded to its width. ## What other tools call it Meridian's classification; an independent blind rating agreed on 86.2% of 312 rows (exact class, version 2). - Azure Data Factory: [`Delimited text format (sink)`](https://learn.microsoft.com/en-us/azure/data-factory/format-delimited-text) (read 2026-09-27) - Apache DataFusion: [`Data Insert: CSV`](https://datafusion.apache.org/user-guide/features.html) (read 2026-09-27) - Apache DataFusion: [`write_csv`](https://docs.rs/datafusion/latest/datafusion/dataframe/struct.DataFrame.html) (read 2026-09-27) - Duckle: [`CSV`](https://github.com/slothflowlabs/duckle/blob/f85f8960edfb6efbf4cb89d58a7b32e16df0e867/website/docs/components.html) (read 2026-09-25) - Duckle: [`TSV`](https://github.com/slothflowlabs/duckle/blob/f85f8960edfb6efbf4cb89d58a7b32e16df0e867/website/docs/components.html) (read 2026-09-25) - EasyMorph: [`Export into delimited text file`](https://help.easymorph.com/doku.php?id=transformations:exporttext) (read 2026-09-27) - AWS Glue: [`CSV (write)`](https://docs.aws.amazon.com/glue/latest/dg/aws-glue-programming-etl-format-csv-home.html) (read 2026-09-27) - Apache Hop: [`Beam file output`](https://hop.apache.org/manual/latest/pipeline/transforms/beamfileoutput.html) (read 2026-09-27) - Apache Hop: [`Neo4j generate CSVs`](https://hop.apache.org/manual/latest/pipeline/transforms/neo4j-gencsv.html) (read 2026-09-27) - Apache Hop: [`Spark file output`](https://hop.apache.org/manual/next/pipeline/transforms/spark-file-output.html) (read 2026-09-27) - Apache Hop: [`Text File Output`](https://hop.apache.org/manual/latest/pipeline/transforms/textfileoutput.html) (read 2026-09-27) - KNIME Analytics Platform: [`CSV Writer`](https://api.hub.knime.com/nodes/*mPMx3pzMHtI9Qk5G?details=full) (read 2026-09-27) - Apache NiFi: [`CSVRecordSetWriter`](https://nifi.apache.org/components/org.apache.nifi.csv.CSVRecordSetWriter/) (read 2026-09-27) - OpenRefine: [`Custom tabular exporter`](https://openrefine.org/docs/manual/exporting#custom-tabular-exporter) (read 2026-09-27) - OpenRefine: [`Tab-separated value (TSV) or Comma-separated value (CSV)`](https://openrefine.org/docs/manual/exporting#export-data) (read 2026-09-27) - Pentaho Data Integration: [`Hadoop File Output`](https://docs.pentaho.com/pdia-data-integration/9.3-data-integration/pdi-transformation-steps-reference-overview) (read 2026-09-27) - Pentaho Data Integration: [`S3 File Output`](https://docs.pentaho.com/pdia-data-integration/9.3-data-integration/pdi-transformation-steps-reference-overview) (read 2026-09-27) - Pentaho Data Integration: [`Text File Output`](https://docs.pentaho.com/pdia-data-integration/9.3-data-integration/pdi-transformation-steps-reference-overview) (read 2026-09-27) - Pentaho Data Integration: [`Text file output (deprecated)`](https://docs.pentaho.com/pdia-data-integration/9.3-data-integration/pdi-transformation-steps-reference-overview) (read 2026-09-27) - Polars: [`DataFrame.write_clipboard`](https://docs.pola.rs/api/python/stable/reference/io.html) (read 2026-09-27) - Polars: [`DataFrame.write_csv`](https://docs.pola.rs/api/python/stable/reference/io.html) (read 2026-09-27) - Polars: [`LazyFrame.sink_csv`](https://docs.pola.rs/api/python/stable/reference/io.html) (read 2026-09-27) - RapidMiner Studio: [`Write CSV`](https://docs.rapidminer.com/latest/studio/operators/data_access/files/write/write_csv.html) (read 2026-09-27) - Tableau Prep: [`Comma Separated Value (.csv)`](https://help.tableau.com/current/prep/en-us/prep_save_share.htm) (read 2026-09-27) - Talend: [`tFileOutputDelimited`](https://help.qlik.com/talend/en-US/components/8.0/delimited/delimited-component) (read 2026-09-27) - Talend: [`tFileOutputMSDelimited`](https://help.qlik.com/talend/en-US/components/8.0/ms-delimited/ms-delimited-component) (read 2026-09-27) - Talend: [`tFileOutputMSPositional`](https://help.qlik.com/talend/en-US/components/8.0/ms-positional/ms-positional-component) (read 2026-09-27) - Talend: [`tFileOutputPositional`](https://help.qlik.com/talend/en-US/components/8.0/positional/positional-component) (read 2026-09-27) - VisiData: [`csv (saver)`](https://github.com/saulpw/visidata/blob/7609212ec2febafa9caba7183cbebfaf49627909/visidata/loaders/csv.py#L85) (read 2026-09-23) - VisiData: [`fixed (saver)`](https://github.com/saulpw/visidata/blob/7609212ec2febafa9caba7183cbebfaf49627909/visidata/loaders/fixed_width.py#L144) (read 2026-09-23) - VisiData: [`lsv (saver)`](https://github.com/saulpw/visidata/blob/7609212ec2febafa9caba7183cbebfaf49627909/visidata/loaders/lsv.py#L14) (read 2026-09-23) - VisiData: [`psv (saver)`](https://github.com/saulpw/visidata/blob/7609212ec2febafa9caba7183cbebfaf49627909/visidata/loaders/psv.py#L15) (read 2026-09-23) - VisiData: [`tsv (saver)`](https://github.com/saulpw/visidata/blob/7609212ec2febafa9caba7183cbebfaf49627909/visidata/loaders/tsv.py#L99) (read 2026-09-23) - VisiData: [`usv (saver)`](https://github.com/saulpw/visidata/blob/7609212ec2febafa9caba7183cbebfaf49627909/visidata/loaders/usv.py#L16) (read 2026-09-23) - Yggdrasil Decision Forests: [`csv: (write)`](https://github.com/google/yggdrasil-decision-forests/blob/0a54b57c95ff0cf42ecf0310ace0513a4f32cb65/yggdrasil_decision_forests/dataset/csv_example_writer.h) (read 2026-09-27)