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> Documentation for INTO OUTFILE Clause

# INTO OUTFILE Clause

`INTO OUTFILE` clause redirects the result of a `SELECT` query to a file on the **client** side.

Compressed files are supported. Compression type is detected by the extension of the file name (mode `'auto'` is used by default). Or it can be explicitly specified in a `COMPRESSION` clause. The compression level for a certain compression type can be specified in a `LEVEL` clause.

**Syntax**

```sql theme={null}
SELECT <expr_list> INTO OUTFILE file_name [AND STDOUT] [APPEND | TRUNCATE] [COMPRESSION type [LEVEL level]]
```

`file_name` and `type` are string literals. Supported compression types are: `'none'`, `'gzip'`, `'deflate'`, `'br'`, `'xz'`, `'zstd'`, `'lz4'`, `'bz2'`.

`level` is a numeric literal. Positive integers in following ranges are supported: `1-12` for `lz4` type, `1-22` for `zstd` type and `1-9` for other compression types.

<h2 id="implementation-details">
  Implementation Details
</h2>

* This functionality is available in the [command-line client](/concepts/features/interfaces/client) and [clickhouse-local](/concepts/features/tools-and-utilities/clickhouse-local). Thus a query sent via [HTTP interface](/concepts/features/interfaces/http) will fail.
* The query will fail if a file with the same file name already exists.
* The default [output format](/reference/formats/index) is `TabSeparated` (like in the command-line client batch mode). Use [FORMAT](/reference/statements/select/format) clause to change it.
* If `AND STDOUT` is mentioned in the query then the output that is written to the file is also displayed on standard output. If used with compression, the plaintext is displayed on standard output.
* If `APPEND` is mentioned in the query then the output is appended to an existing file. If compression is used, append cannot be used.
* When writing to a file that already exists, `APPEND` or `TRUNCATE` must be used.

**Example**

Execute the following query using [command-line client](/concepts/features/interfaces/client):

```bash title="Query" theme={null}
clickhouse-client --query="SELECT 1,'ABC' INTO OUTFILE 'select.gz' FORMAT CSV;"
zcat select.gz 
```

```text title="Response" theme={null}
1,"ABC"
```