mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-30 11:32:03 +00:00
132 lines
4.5 KiB
Markdown
132 lines
4.5 KiB
Markdown
---
|
||
slug: /zh/sql-reference/table-functions/s3
|
||
sidebar_position: 45
|
||
sidebar_label: s3
|
||
---
|
||
|
||
# S3 表函数 {#s3-table-function}
|
||
|
||
提供类似于表的接口来 select/insert [Amazon S3](https://aws.amazon.com/s3/)中的文件。这个表函数类似于[hdfs](../../sql-reference/table-functions/hdfs.md)，但提供了 S3 特有的功能。
|
||
|
||
**语法**
|
||
|
||
``` sql
|
||
s3(path, [aws_access_key_id, aws_secret_access_key,] format, structure, [compression])
|
||
```
|
||
|
||
**参数**
|
||
|
||
- `path` — 带有文件路径的 Bucket url。在只读模式下支持以下通配符: `*`, `?`, `{abc,def}` 和 `{N..M}` 其中 `N`, `M` 是数字, `'abc'`, `'def'` 是字符串. 更多信息见[下文](#wildcards-in-path).
|
||
- `format` — 文件的[格式](../../interfaces/formats.md#formats).
|
||
- `structure` — 表的结构. 格式像这样 `'column1_name column1_type, column2_name column2_type, ...'`.
|
||
- `compression` — 压缩类型. 支持的值: `none`, `gzip/gz`, `brotli/br`, `xz/LZMA`, `zstd/zst`. 参数是可选的. 默认情况下，通过文件扩展名自动检测压缩类型.
|
||
|
||
**返回值**
|
||
|
||
一个具有指定结构的表，用于读取或写入指定文件中的数据。
|
||
|
||
**示例**
|
||
|
||
从 S3 文件`https://storage.yandexcloud.net/my-test-bucket-768/data.csv`中选择表格的前两行:
|
||
|
||
``` sql
|
||
SELECT *
|
||
FROM s3('https://storage.yandexcloud.net/my-test-bucket-768/data.csv', 'CSV', 'column1 UInt32, column2 UInt32, column3 UInt32')
|
||
LIMIT 2;
|
||
```
|
||
|
||
``` text
|
||
┌─column1─┬─column2─┬─column3─┐
|
||
│ 1 │ 2 │ 3 │
|
||
│ 3 │ 2 │ 1 │
|
||
└─────────┴─────────┴─────────┘
|
||
```
|
||
|
||
类似的情况，但来源是`gzip`压缩的文件:
|
||
|
||
``` sql
|
||
SELECT *
|
||
FROM s3('https://storage.yandexcloud.net/my-test-bucket-768/data.csv.gz', 'CSV', 'column1 UInt32, column2 UInt32, column3 UInt32', 'gzip')
|
||
LIMIT 2;
|
||
```
|
||
|
||
``` text
|
||
┌─column1─┬─column2─┬─column3─┐
|
||
│ 1 │ 2 │ 3 │
|
||
│ 3 │ 2 │ 1 │
|
||
└─────────┴─────────┴─────────┘
|
||
```
|
||
|
||
## 用法 {#usage-examples}
|
||
|
||
假设我们在S3上有几个文件，URI如下:
|
||
|
||
- 'https://storage.yandexcloud.net/my-test-bucket-768/some_prefix/some_file_1.csv'
|
||
- 'https://storage.yandexcloud.net/my-test-bucket-768/some_prefix/some_file_2.csv'
|
||
- 'https://storage.yandexcloud.net/my-test-bucket-768/some_prefix/some_file_3.csv'
|
||
- 'https://storage.yandexcloud.net/my-test-bucket-768/some_prefix/some_file_4.csv'
|
||
- 'https://storage.yandexcloud.net/my-test-bucket-768/another_prefix/some_file_1.csv'
|
||
- 'https://storage.yandexcloud.net/my-test-bucket-768/another_prefix/some_file_2.csv'
|
||
- 'https://storage.yandexcloud.net/my-test-bucket-768/another_prefix/some_file_3.csv'
|
||
- 'https://storage.yandexcloud.net/my-test-bucket-768/another_prefix/some_file_4.csv'
|
||
|
||
计算以数字1至3结尾的文件的总行数:
|
||
|
||
``` sql
|
||
SELECT count(*)
|
||
FROM s3('https://storage.yandexcloud.net/my-test-bucket-768/{some,another}_prefix/some_file_{1..3}.csv', 'CSV', 'name String, value UInt32')
|
||
```
|
||
|
||
``` text
|
||
┌─count()─┐
|
||
│ 18 │
|
||
└─────────┘
|
||
```
|
||
|
||
计算这两个目录中所有文件的行的总量:
|
||
|
||
``` sql
|
||
SELECT count(*)
|
||
FROM s3('https://storage.yandexcloud.net/my-test-bucket-768/{some,another}_prefix/*', 'CSV', 'name String, value UInt32')
|
||
```
|
||
|
||
``` text
|
||
┌─count()─┐
|
||
│ 24 │
|
||
└─────────┘
|
||
```
|
||
|
||
!!! warning "Warning"
|
||
如果文件列表中包含有从零开头的数字范围，请对每个数字分别使用带括号的结构，或者使用`?`。
|
||
|
||
计算名为 `file-000.csv`, `file-001.csv`, … , `file-999.csv` 文件的总行数:
|
||
|
||
``` sql
|
||
SELECT count(*)
|
||
FROM s3('https://storage.yandexcloud.net/my-test-bucket-768/big_prefix/file-{000..999}.csv', 'CSV', 'name String, value UInt32');
|
||
```
|
||
|
||
``` text
|
||
┌─count()─┐
|
||
│ 12 │
|
||
└─────────┘
|
||
```
|
||
|
||
插入数据到 `test-data.csv.gz` 文件:
|
||
|
||
``` sql
|
||
INSERT INTO FUNCTION s3('https://storage.yandexcloud.net/my-test-bucket-768/test-data.csv.gz', 'CSV', 'name String, value UInt32', 'gzip')
|
||
VALUES ('test-data', 1), ('test-data-2', 2);
|
||
```
|
||
|
||
从已有的表插入数据到 `test-data.csv.gz` 文件:
|
||
|
||
``` sql
|
||
INSERT INTO FUNCTION s3('https://storage.yandexcloud.net/my-test-bucket-768/test-data.csv.gz', 'CSV', 'name String, value UInt32', 'gzip')
|
||
SELECT name, value FROM existing_table;
|
||
```
|
||
|
||
**另请参阅**
|
||
|
||
- [S3 引擎](../../engines/table-engines/integrations/s3.md)
|