---
metadata:
  - name: generator
    content: Diplodoc Platform v5.50.6
alternate:
  - https://ydb.tech/docs/en/yql/reference/syntax/create-external-table.md?version=main
  - https://ydb.tech/docs/ru/yql/reference/syntax/create-external-table.md?version=main
sourcePath: en/core/yql/reference/syntax/create-external-table.md
---
> **Documentation Index:** Fetch the complete configuration index at https://ydb.tech/docs/en/llms.txt

# CREATE EXTERNAL TABLE

The `CREATE EXTERNAL TABLE` statement creates an [external table](https://ydb.tech/docs/en/concepts/datamodel/external_table.md?version=main) with the given schema.

```yql
CREATE EXTERNAL TABLE table_name (
  column1 type1,
  column2 type2 NOT NULL,
  ...
  columnN typeN NULL
) WITH (
  DATA_SOURCE="data_source_name",
  LOCATION="path",
  FORMAT="format_name",
  COMPRESSION="compression_name"
);
```

Where:

* `column1 type1`, `columnN typeN NULL` — column definitions and types;
* `data_source_name` — name of the [connection](https://ydb.tech/docs/en/concepts/datamodel/external_data_source.md?version=main) to S3 (Object Storage).
* `path` — path inside the data bucket. The path must refer to an existing folder in the bucket.
* `format_name` — one of the [supported storage formats](https://ydb.tech/docs/en/concepts/query_execution/federated_query/s3/formats.md?version=main).
* `compression_name` — one of the [supported compression algorithms](https://ydb.tech/docs/en/concepts/query_execution/federated_query/s3/formats.md?version=main#compression).

Only a limited subset of data types is allowed:

- `Bool`.
- `Int8`, `Uint8`, `Int16`, `Uint16`, `Int32`, `Uint32`, `Int64`, `Uint64`.
- `Float`, `Double`.
- `Date`, `DateTime`.
- `String`, `Utf8`.

Without extra modifiers, a column has an [optional type](https://ydb.tech/docs/en/yql/reference/types/optional.md?version=main) and may contain `NULL`. Use `NOT NULL` for a non-optional column.

## Example

The following creates an external table `s3_test_data` with string columns `key` and `value` in CSV format under `test_folder` in the bucket, using external data source `bucket`:

```yql
CREATE EXTERNAL TABLE s3_test_data (
  key Utf8 NOT NULL,
  value Utf8 NOT NULL
) WITH (
  DATA_SOURCE="bucket",
  LOCATION="folder",
  FORMAT="csv_with_names",
  COMPRESSION="gzip"
);
```