# Emit a fixed number of rows

Acquire / generate

A variant of [Generate rows](https://meridian.online/operations/generate-rows).

Emit N empty, blank or identical rows, or an empty table with set columns.

Page: <https://meridian.online/operations/generate-rows/emit-a-fixed-number-of-rows>

## Status

Runs as a SQL step.

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

## The DuckDB step

emit a number of identical, empty or blank rows and an empty table with set columns

```sql
CREATE TEMP TABLE identical AS SELECT 'x' AS v FROM range(3);
CREATE TEMP TABLE empty_rows AS SELECT NULL::VARCHAR AS a, NULL::INTEGER AS b FROM range(4);
CREATE TEMP TABLE blank_rows AS SELECT ''::VARCHAR AS a FROM range(2);
CREATE TEMP TABLE no_rows (id INTEGER, name VARCHAR, joined DATE);
SELECT * FROM identical; SELECT * FROM empty_rows; SELECT * FROM blank_rows; SELECT * FROM no_rows;
SELECT CASE WHEN ((SELECT count(*) = 3 AND count(DISTINCT v) = 1 FROM identical) AND (SELECT count(*) = 4 AND count(a) = 0 AND count(b) = 0 FROM empty_rows) AND (SELECT count(*) = 2 AND count(a) = 2 AND max(length(a)) = 0 FROM blank_rows) AND (SELECT count(*) FROM no_rows) = 0 AND (SELECT list(column_name || ' ' || column_type) FROM (DESCRIBE no_rows)) = ['id INTEGER', 'name VARCHAR', 'joined DATE']) THEN 'as expected' ELSE error('the rows were not 3 identical, 4 empty and 2 blank, or the empty table did not keep its 3 typed columns') END AS verdict;
```

The statement builds its own data.

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).

- DuckDB: `repeat` (read 2026-09-27)
- DuckDB: `repeat_row` (read 2026-09-27)
- Apache Hop: [`Row Generator`](https://hop.apache.org/manual/latest/pipeline/transforms/rowgenerator.html) (read 2026-09-27)
- KNIME Analytics Platform: [`Table Structure Creator`](https://api.hub.knime.com/nodes/*4FYTUeYe0PWfhxoP?details=full) (read 2026-09-27)
- Apache NiFi: [`DuplicateFlowFile`](https://nifi.apache.org/components/org.apache.nifi.processors.standard.DuplicateFlowFile/) (read 2026-09-27)
- Pentaho Data Integration: [`Generate Rows`](https://docs.pentaho.com/pdia-data-integration/9.3-data-integration/pdi-transformation-steps-reference-overview) (read 2026-09-27)
- Polars: [`DataFrame.clear`](https://docs.pola.rs/api/python/stable/reference/dataframe/modify_select.html) (read 2026-09-27)