> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-detect-table-modification.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# كيف يمكنني تحويل الملفات من Parquet إلى CSV أو JSON؟
> تعرّف على كيفية استخدام أداة `clickhouse-local` من ClickHouse لتحويل ملفات Parquet بسهولة إلى صيغ CSV أو JSON.
{frontMatter.description}
## تحويل الملفات من Parquet إلى CSV أو JSON
يمكنك استخدام `clickhouse-local` لتحويل الملفات بين أي من [تنسيقات الإدخال والإخراج](/ar/reference/formats/index) التي يدعمها ClickHouse (وهي أكثر من 70 تنسيقًا مختلفًا!). في هذه المقالة، سنحوّل ملف Parquet في S3 إلى ملفي CSV وJSON.
لنبدأ من البداية. يوفّر ClickHouse مجموعة من [دوال الجداول](/ar/reference/functions/table-functions/index) التي تقرأ من الملفات وقواعد البيانات والموارد الأخرى، ثم تحوّل البيانات إلى جدول. للتوضيح، لنفترض أن لدينا ملف Parquet في S3. سنستخدم دالة الجدول `s3` لقراءته (ويعرف ClickHouse أنه ملف Parquet استنادًا إلى اسم الملف).
لكن أولًا، لننزّل الملف التنفيذي `clickhouse`:
```bash theme={null}
curl https://clickhouse.com/ | sh
```
## الوصول إلى البيانات باستخدام دالة الجدول
لنتحقق من إمكانية قراءة الملف باستخدام `DESCRIBE` على الجدول الناتج الذي تُنشئه دالة الجدول `s3`:
```bash theme={null}
./clickhouse local -q "DESCRIBE s3('https://datasets-documentation.s3.eu-west-3.amazonaws.com/house_parquet/house_0.parquet')"
```
يحتوي هذا الملف تحديدًا على أسعار المنازل للعقارات التي بيعت في المملكة المتحدة. تبدو الاستجابة كما يلي:
```response theme={null}
price Nullable(Int64)
date Nullable(UInt16)
postcode1 Nullable(String)
postcode2 Nullable(String)
type Nullable(String)
is_new Nullable(UInt8)
duration Nullable(String)
addr1 Nullable(String)
addr2 Nullable(String)
street Nullable(String)
locality Nullable(String)
town Nullable(String)
district Nullable(String)
county Nullable(String)
```
يمكنك تنفيذ أي استعلام تريده على البيانات. على سبيل المثال، لنرَ أيُّ البلدات لديها أعلى متوسط لأسعار المنازل:
```bash theme={null}
./clickhouse local -q "SELECT
town,
avg(price) AS avg_price
FROM s3('https://datasets-documentation.s3.eu-west-3.amazonaws.com/house_parquet/house_0.parquet')
GROUP BY town
ORDER BY avg_price DESC
LIMIT 10"
```
تكون الاستجابة كما يلي:
```bash theme={null}
GATWICK 16818750
CHALFONT ST GILES 938090.0985915493
VIRGINIA WATER 789301.1320224719
COBHAM 699874.7111622555
BEACONSFIELD 677247.5483146068
ESHER 616004.6888297872
KESTON 607585.8597560975
GERRARDS CROSS 566330.2959086584
ASCOT 551491.2975753123
WEYBRIDGE 548974.828692494
```
## حوِّل ملف Parquet إلى ملف CSV
يمكنك إرسال نتيجة أي استعلام SQL إلى ملف. لنأخذ جميع الأعمدة من ملف Parquet الموجود لدينا في S3 ونرسل الناتج إلى ملف CSV جديد. وبما أن ملف الإخراج ينتهي بـ `.csv`، فإن ClickHouse يعرف أنه يجب استخدام صيغة الإخراج `CSV`:
```bash theme={null}
./clickhouse local -q "SELECT *
FROM s3('https://datasets-documentation.s3.eu-west-3.amazonaws.com/house_parquet/house_0.parquet')
INTO OUTFILE 'house_prices.csv'"
```
لنتحقق من نجاح ذلك:
```response theme={null}
$ tail house_prices.csv
70000,10508,"YO8","9XN","detached",0,"freehold","7","","POPPY CLOSE","SELBY","SELBY","SELBY","NORTH YORKSHIRE"
130000,14274,"YO8","9XP","detached",0,"freehold","10","","HEATHER CLOSE","","SELBY","SELBY","NORTH YORKSHIRE"
150000,18180,"YO8","9XP","detached",0,"freehold","11","","HEATHER CLOSE","","SELBY","SELBY","NORTH YORKSHIRE"
157000,18088,"YO8","9XP","detached",0,"freehold","12","","HEATHER CLOSE","","SELBY","SELBY","NORTH YORKSHIRE"
134000,17333,"YO8","9XP","semi-detached",0,"freehold","16","","HEATHER CLOSE","","SELBY","SELBY","NORTH YORKSHIRE"
250000,13405,"YO8","9YA","detached",0,"freehold","6","","YORKDALE COURT","HAMBLETON","SELBY","SELBY","NORTH YORKSHIRE"
59500,11166,"YO8","9YB","semi-detached",0,"freehold","4","","YORKDALE DRIVE","HAMBLETON","SELBY","SELBY","NORTH YORKSHIRE"
142500,17648,"YO8","9YB","semi-detached",0,"freehold","4A","","YORKDALE DRIVE","HAMBLETON","SELBY","SELBY","NORTH YORKSHIRE"
230000,15125,"YO8","9YD","detached",0,"freehold","1","","ONE ACRE GARTH","HAMBLETON","SELBY","SELBY","NORTH YORKSHIRE"
250000,15950,"YO8","9YD","detached",0,"freehold","3","","ONE ACRE GARTH","HAMBLETON","SELBY","SELBY","NORTH YORKSHIRE"
```
## حوّل ملف Parquet إلى تنسيق JSON
لتحويل ملف Parquet إلى JSON، ما عليك سوى تغيير امتداد ملف الإخراج:
```bash theme={null}
./clickhouse local -q "SELECT *
FROM s3('https://datasets-documentation.s3.eu-west-3.amazonaws.com/house_parquet/house_0.parquet')
INTO OUTFILE 'house_prices.ndjson'"
```
لنتأكد من نجاح العملية:
```response theme={null}
$ tail house_prices.ndjson
{"price":"70000","date":10508,"postcode1":"YO8","postcode2":"9XN","type":"detached","is_new":0,"duration":"freehold","addr1":"7","addr2":"","street":"POPPY CLOSE","locality":"SELBY","town":"SELBY","district":"SELBY","county":"NORTH YORKSHIRE"}
{"price":"130000","date":14274,"postcode1":"YO8","postcode2":"9XP","type":"detached","is_new":0,"duration":"freehold","addr1":"10","addr2":"","street":"HEATHER CLOSE","locality":"","town":"SELBY","district":"SELBY","county":"NORTH YORKSHIRE"}
{"price":"150000","date":18180,"postcode1":"YO8","postcode2":"9XP","type":"detached","is_new":0,"duration":"freehold","addr1":"11","addr2":"","street":"HEATHER CLOSE","locality":"","town":"SELBY","district":"SELBY","county":"NORTH YORKSHIRE"}
{"price":"157000","date":18088,"postcode1":"YO8","postcode2":"9XP","type":"detached","is_new":0,"duration":"freehold","addr1":"12","addr2":"","street":"HEATHER CLOSE","locality":"","town":"SELBY","district":"SELBY","county":"NORTH YORKSHIRE"}
{"price":"134000","date":17333,"postcode1":"YO8","postcode2":"9XP","type":"semi-detached","is_new":0,"duration":"freehold","addr1":"16","addr2":"","street":"HEATHER CLOSE","locality":"","town":"SELBY","district":"SELBY","county":"NORTH YORKSHIRE"}
{"price":"250000","date":13405,"postcode1":"YO8","postcode2":"9YA","type":"detached","is_new":0,"duration":"freehold","addr1":"6","addr2":"","street":"YORKDALE COURT","locality":"HAMBLETON","town":"SELBY","district":"SELBY","county":"NORTH YORKSHIRE"}
{"price":"59500","date":11166,"postcode1":"YO8","postcode2":"9YB","type":"semi-detached","is_new":0,"duration":"freehold","addr1":"4","addr2":"","street":"YORKDALE DRIVE","locality":"HAMBLETON","town":"SELBY","district":"SELBY","county":"NORTH YORKSHIRE"}
{"price":"142500","date":17648,"postcode1":"YO8","postcode2":"9YB","type":"semi-detached","is_new":0,"duration":"freehold","addr1":"4A","addr2":"","street":"YORKDALE DRIVE","locality":"HAMBLETON","town":"SELBY","district":"SELBY","county":"NORTH YORKSHIRE"}
{"price":"230000","date":15125,"postcode1":"YO8","postcode2":"9YD","type":"detached","is_new":0,"duration":"freehold","addr1":"1","addr2":"","street":"ONE ACRE GARTH","locality":"HAMBLETON","town":"SELBY","district":"SELBY","county":"NORTH YORKSHIRE"}
{"price":"250000","date":15950,"postcode1":"YO8","postcode2":"9YD","type":"detached","is_new":0,"duration":"freehold","addr1":"3","addr2":"","street":"ONE ACRE GARTH","locality":"HAMBLETON","town":"SELBY","district":"SELBY","county":"NORTH YORKSHIRE"}
```
## تحويل CSV إلى Parquet
يعمل هذا في كلا الاتجاهين - إذ يمكننا بسهولة قراءة ملف CSV الجديد وإخراجه كملف Parquet. ويمكن لـ ClickHouse قراءة الملف المحلي `house_prices.csv` باستخدام دالة الجدول `file`، كما يُخرج ClickHouse الملف بتنسيق Parquet استنادًا إلى امتداد اسم الملف `.parquet` (أو كان بإمكاننا إضافة بند `FORMAT Parquet`):
```bash theme={null}
./clickhouse local -q "SELECT *
FROM file('house_prices.csv')
INTO OUTFILE 'house_prices.parquet'"
```
كما ذكرنا أعلاه، يمكنك استخدام أيٍّ من [تنسيقات الإدخال والإخراج](/ar/reference/formats/index) في ClickHouse مع `clickhouse local` لتحويل الملفات بسهولة إلى صيغ مختلفة.