Difference between revisions of "DuckDB Cheatsheet"
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The Parquet file dump of the Open Food Facts database contains a variety of data in different format, such as string, list, struct, timestamp,... | The Parquet file dump of the Open Food Facts database contains a variety of data in different format, such as string, list, struct, timestamp,... | ||
− | In this | + | In this cheat sheet, we will learn how to use the Parquet dump using DuckDB to perform data analysis, by solving some of the most common use-cases asked by the community. |
− | We assume that you've downloaded the <code>food.parquet</code> file locally, and that you've launched | + | We assume that you've downloaded the <code>food.parquet</code> file locally, and that you've launched DuckDB CLI. (see [[Reusing Open Food Facts Data#Parquet file hosted on Hugging Face .28beta.29|Reusing Open Food Facts Data]]). |
+ | |||
+ | ==== Modify the type of output ==== | ||
+ | By default, DuckDB adopts its own display mode. But this mode truncates the display when the output is too long. There are many others outputs, see [https://duckdb.org/docs/api/cli/output_formats.html DuckDB documentation about them]. | ||
+ | |||
+ | ==== Describe the data ==== | ||
+ | It's interesting to have the whole list of fields and their characteristics. | ||
+ | .mode box -- comment: change display mode to nice table | ||
+ | describe select * from 'food.parquet'; | ||
==== Creating a new parquet file for my country ==== | ==== Creating a new parquet file for my country ==== |
Revision as of 16:25, 21 January 2025
The Parquet file dump of the Open Food Facts database contains a variety of data in different format, such as string, list, struct, timestamp,...
In this cheat sheet, we will learn how to use the Parquet dump using DuckDB to perform data analysis, by solving some of the most common use-cases asked by the community.
We assume that you've downloaded the food.parquet
file locally, and that you've launched DuckDB CLI. (see Reusing Open Food Facts Data).
Modify the type of output
By default, DuckDB adopts its own display mode. But this mode truncates the display when the output is too long. There are many others outputs, see DuckDB documentation about them.
Describe the data
It's interesting to have the whole list of fields and their characteristics.
.mode box -- comment: change display mode to nice table describe select * from 'food.parquet';
Creating a new parquet file for my country
COPY ( SELECT * FROM 'food.parquet' WHERE 'en:canada' IN food.countries_tags ) TO 'off-canada.parquet' (FORMAT 'parquet', COMPRESSION 'zstd');
Display product name (for main language) of all products of with category en:butters
SELECT code, unnest( list_filter (product_name, x -> x.lang == 'main') ) ['text'] FROM 'food.parquet' WHERE list_contains (categories_tags, 'en:milks') LIMIT 10; ┌───────────────┬─────────────────────────────────────────────────────────────────────┐ │ code │ unnest(list_filter(product_name, (x -> (x.lang = 'main'))))['text'] │ │ varchar │ varchar │ ├───────────────┼─────────────────────────────────────────────────────────────────────┤ │ 0011110807625 │ Quality food centers, salted butter │ │ 0011110808998 │ Unsalted Butter │ │ 0011110842640 │ Ralphs, Salted Sticks, Butter │ │ 0011110852878 │ Salted butter │ │ 0011110854384 │ Qfc, unsalted butter │ │ 0011110862600 │ King Soopers City Market, Salted Butter │ │ 0011110863256 │ Salted Butter │ │ 0011110863270 │ Unsalted Butter │ │ 0011110893017 │ Salted Butter │ │ 0011110893055 │ Unsalted butter sticks │ ├───────────────┴─────────────────────────────────────────────────────────────────────┤ │ 10 rows 2 columns │ └─────────────────────────────────────────────────────────────────────────────────────┘
Who are the biggest contributors?
Ex: Top 10 best contributors in OFF
SELECT creator, count(*) AS count FROM read_parquet('food.parquet') GROUP BY creator ORDER BY count DESC LIMIT 10; ┌────────────────────────────┬─────────┐ │ creator │ count │ │ varchar │ int64 │ ├────────────────────────────┼─────────┤ │ kiliweb │ 1883982 │ │ foodvisor │ 208270 │ │ openfoodfacts-contributors │ 199459 │ │ usda-ndb-import │ 169554 │ │ org-database-usda │ 134461 │ │ prepperapp │ 110841 │ │ macrofactor │ 92148 │ │ foodless │ 87839 │ │ smoothie-app │ 74339 │ │ inf │ 37999 │ ├────────────────────────────┴─────────┤ │ 10 rows 2 columns │ └──────────────────────────────────────┘
Number of added products per year
--entry_dates_tags is a list of texts. We take the value at position 3: the year SELECT entry_dates_tags[3] AS year, count(*) AS count FROM read_parquet('food.parquet') GROUP BY year ORDER BY year DESC; ┌─────────┬────────┐ │ year │ count │ │ varchar │ int64 │ ├─────────┼────────┤ │ 2024 │ 463257 │ │ 2023 │ 361240 │ │ 2022 │ 598326 │ │ 2021 │ 514052 │ │ 2020 │ 466269 │ │ 2019 │ 364272 │ │ 2018 │ 318010 │ │ 2017 │ 279737 │ │ 2016 │ 44618 │ │ 2015 │ 33968 │ │ 2014 │ 12892 │ │ 2013 │ 9587 │ │ 2012 │ 4267 │ │ 1970 │ 3 │ │ │ 1 │ ├─────────┴────────┤ │ 15 rows │ └──────────────────┘
Search for a string in a list
Eg. search in the list allergen_tags
values containing fr:
. You have to convert the array into a string using the array_to_string
.
SELECT count(code) as nb, ANY_VALUE(code), allergens_tags FROM 'food.parquet' where regexp_matches(array_to_string(allergens_tags, ','), 'fr:') group by allergens_tags order by nb desc
How many images where uploaded in 2024?
SELECT SUM(images_filter_count) AS image_count FROM ( SELECT len ( list_filter ( images, x -> struct_extract (x, 'uploaded_t') > epoch (TIMESTAMP '2024-01-01 00:00:00') AND struct_extract (x, 'uploaded_t') < epoch (TIMESTAMP '2025-01-01 00:00:00') ) ) as images_filter_count FROM 'food.parquet' ); ┌─────────────┐ │ image_count │ │ int128 │ ├─────────────┤ │ 716207 │ └─────────────┘