# Split text into a list

Shape / columns

A variant of [Split a column](https://meridian.online/operations/split-a-column).

Split a text value into one list value of its parts, in a single column.

Page: <https://meridian.online/operations/split-a-column/split-text-into-a-list>

## Status

Runs as a SQL step.

arcform carries it as a `sql:` step today.

## The DuckDB step

split text into one list column

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 result AS
SELECT order_id, string_split(tags, '|') AS tag_list FROM orders;
SELECT * FROM result;
SELECT CASE WHEN ((SELECT list(column_name) FROM (DESCRIBE result)) = ['order_id', 'tag_list'] AND (SELECT tag_list FROM result WHERE order_id = 10) = ['a', 'b', 'c'] AND (SELECT sum(len(tag_list)) FROM result) = 13 AND (SELECT count(*) FILTER (WHERE tag_list IS NULL) FROM result) = 2) THEN 'as expected' ELSE error('the tags were not split into one list column of 13 parts with the two missing tags left null') 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).

- Duckle: [`Split`](https://github.com/slothflowlabs/duckle/blob/f85f8960edfb6efbf4cb89d58a7b32e16df0e867/website/docs/components.html) (read 2026-09-25)
- AWS Glue: [`Split String`](https://docs.aws.amazon.com/glue/latest/dg/transforms-split-string.html) (read 2026-09-27)
- Ibis: [`StringSplit`](https://github.com/ibis-project/ibis/blob/05d2b293344e86cb41c1a426071734f7e270335a/ibis/expr/operations/strings.py) (read 2026-09-27)
- OpenRefine: [`String parsing and splitting`](https://openrefine.org/docs/manual/grelfunctions#string-parsing-and-splitting) (read 2026-09-27)
- Polars: [`Expr.str: split (group)`](https://docs.pola.rs/api/python/stable/reference/expressions/string.html) (read 2026-09-27)
- Power Query M: [`Lines functions`](https://learn.microsoft.com/en-us/powerquery-m/lines-functions) (read 2026-09-27)