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* split up select.md * array-join.md basic refactoring * distinct.md basic refactoring * format.md basic refactoring * from.md basic refactoring * group-by.md basic refactoring * having.md basic refactoring * additional index.md refactoring * into-outfile.md basic refactoring * join.md basic refactoring * limit.md basic refactoring * limit-by.md basic refactoring * order-by.md basic refactoring * prewhere.md basic refactoring * adjust operators/index.md links * adjust sample.md links * adjust more links * adjust operatots links * fix some links * adjust aggregate function article titles * basic refactor of remaining select clauses * absolute paths in make_links.sh * run make_links.sh * remove old select.md locations * translate docs/es * translate docs/fr * translate docs/fa * remove old operators.md location * change operators.md links * adjust links in docs/es * adjust links in docs/es * minor texts adjustments * wip * update machine translations to use new links * fix changelog * es build fixes * get rid of some select.md links * temporary adjust ru links * temporary adjust more ru links * improve curly brace handling * adjust ru as well * fa build fix * ru link fixes * zh link fixes * temporary disable part of anchor checks
122 lines
3.9 KiB
Markdown
122 lines
3.9 KiB
Markdown
---
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machine_translated: true
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machine_translated_rev: 72537a2d527c63c07aa5d2361a8829f3895cf2bd
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toc_priority: 37
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toc_title: file
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---
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# file {#file}
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Crea una tabla a partir de un archivo. Esta función de tabla es similar a [URL](url.md) y [Hdfs](hdfs.md) aquel.
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``` sql
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file(path, format, structure)
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```
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**Parámetros de entrada**
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- `path` — The relative path to the file from [user\_files\_path](../../operations/server-configuration-parameters/settings.md#server_configuration_parameters-user_files_path). Soporte de ruta a archivo siguiendo globs en modo de solo lectura: `*`, `?`, `{abc,def}` y `{N..M}` donde `N`, `M` — numbers, \``'abc', 'def'` — strings.
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- `format` — The [formato](../../interfaces/formats.md#formats) del archivo.
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- `structure` — Structure of the table. Format `'column1_name column1_type, column2_name column2_type, ...'`.
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**Valor devuelto**
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Una tabla con la estructura especificada para leer o escribir datos en el archivo especificado.
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**Ejemplo**
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Configuración `user_files_path` y el contenido del archivo `test.csv`:
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``` bash
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$ grep user_files_path /etc/clickhouse-server/config.xml
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<user_files_path>/var/lib/clickhouse/user_files/</user_files_path>
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$ cat /var/lib/clickhouse/user_files/test.csv
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1,2,3
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3,2,1
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78,43,45
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```
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Tabla de`test.csv` y selección de las dos primeras filas de ella:
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``` sql
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SELECT *
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FROM file('test.csv', 'CSV', 'column1 UInt32, column2 UInt32, column3 UInt32')
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LIMIT 2
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```
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``` text
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┌─column1─┬─column2─┬─column3─┐
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│ 1 │ 2 │ 3 │
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│ 3 │ 2 │ 1 │
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└─────────┴─────────┴─────────┘
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```
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``` sql
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-- getting the first 10 lines of a table that contains 3 columns of UInt32 type from a CSV file
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SELECT * FROM file('test.csv', 'CSV', 'column1 UInt32, column2 UInt32, column3 UInt32') LIMIT 10
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```
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**Globs en el camino**
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Múltiples componentes de ruta de acceso pueden tener globs. Para ser procesado, el archivo debe existir y coincidir con todo el patrón de ruta (no solo el sufijo o el prefijo).
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- `*` — Substitutes any number of any characters except `/` incluyendo cadena vacía.
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- `?` — Substitutes any single character.
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- `{some_string,another_string,yet_another_one}` — Substitutes any of strings `'some_string', 'another_string', 'yet_another_one'`.
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- `{N..M}` — Substitutes any number in range from N to M including both borders.
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Construcciones con `{}` son similares a la [función de tabla remota](../../sql-reference/table-functions/remote.md)).
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**Ejemplo**
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1. Supongamos que tenemos varios archivos con las siguientes rutas relativas:
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- ‘some\_dir/some\_file\_1’
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- ‘some\_dir/some\_file\_2’
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- ‘some\_dir/some\_file\_3’
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- ‘another\_dir/some\_file\_1’
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- ‘another\_dir/some\_file\_2’
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- ‘another\_dir/some\_file\_3’
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1. Consulta la cantidad de filas en estos archivos:
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<!-- -->
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``` sql
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SELECT count(*)
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FROM file('{some,another}_dir/some_file_{1..3}', 'TSV', 'name String, value UInt32')
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```
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1. Consulta la cantidad de filas en todos los archivos de estos dos directorios:
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<!-- -->
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``` sql
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SELECT count(*)
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FROM file('{some,another}_dir/*', 'TSV', 'name String, value UInt32')
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```
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!!! warning "Advertencia"
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Si su lista de archivos contiene rangos de números con ceros a la izquierda, use la construcción con llaves para cada dígito por separado o use `?`.
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**Ejemplo**
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Consultar los datos desde archivos nombrados `file000`, `file001`, … , `file999`:
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``` sql
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SELECT count(*)
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FROM file('big_dir/file{0..9}{0..9}{0..9}', 'CSV', 'name String, value UInt32')
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```
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## Virtual Columnas {#virtual-columns}
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- `_path` — Path to the file.
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- `_file` — Name of the file.
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**Ver también**
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- [Virtual columnas](https://clickhouse.tech/docs/en/operations/table_engines/#table_engines-virtual_columns)
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[Artículo Original](https://clickhouse.tech/docs/en/query_language/table_functions/file/) <!--hide-->
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