> ## Documentation Index
> Fetch the complete documentation index at: https://docs.risingwave.com/llms.txt
> Use this file to discover all available pages before exploring further.

# COPY

> Use the `COPY` command to export query results to standard output in TSV format.

The `COPY` command allows you to export query results from RisingWave to standard output (STDOUT) in tab-separated values (TSV) format. This is useful for integrating RisingWave with external systems that can consume PostgreSQL-compatible COPY output, such as ClickHouse's PostgreSQL table engine.

## Syntax

```sql theme={null}
COPY ( query ) TO STDOUT;
```

## Parameters

| Parameter | Description                                       |
| :-------- | :------------------------------------------------ |
| *query*   | A SELECT query that specifies the data to export. |

## Output format

The `COPY TO STDOUT` command outputs data in TSV format with the following characteristics:

* Fields are separated by tab characters (`\t`)
* Rows are separated by newline characters (`\n`)
* NULL values are represented as empty fields
* Special characters are escaped:
  * Tab characters in data are escaped as `\t`
  * Newline characters in data are escaped as `\n`
  * Carriage return characters in data are escaped as `\r`
  * Backslash characters in data are escaped as `\\`

## Examples

Export results from a simple query:

```sql Basic example theme={null}
COPY (SELECT id, name FROM users ORDER BY id) TO STDOUT;
```

This outputs data in TSV format:

```
1	Alice
2	Bob
3	Charlie
```

When data contains special characters, they are properly escaped:

```sql Example with special characters theme={null}
CREATE TABLE t (id int, name string);
INSERT INTO t VALUES 
  (1, 'name'), 
  (2, null), 
  (3, E'name1\tname'),
  (4, E'name1\rname'),
  (5, E'name1\nname'),
  (6, E'name1\\name');
FLUSH;

COPY (SELECT name, id FROM t ORDER BY id) TO STDOUT;
```

The output is:

```
name	1
	2
name1\tname	3
name1\rname	4
name1\nname	5
name1\\name	6
```

### Integration with ClickHouse

The `COPY TO STDOUT` command enables ClickHouse to query RisingWave data using the [PostgreSQL table engine](https://clickhouse.com/docs/engines/table-engines/integrations/postgresql). ClickHouse uses this syntax internally when loading data from PostgreSQL-compatible databases.

Example ClickHouse configuration:

```sql theme={null}
CREATE TABLE clickhouse_table
ENGINE = PostgreSQL('risingwave_host:4566', 'database_name', 'table_name', 'user', 'password');
```

ClickHouse will automatically use `COPY () TO STDOUT` to efficiently load data from RisingWave.

## Related topics

* [ClickHouse sink](/integrations/destinations/clickhouse) — Send data from RisingWave to ClickHouse