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SQLite3 convert hex string to int (requires sqlite >= 3.8.3)
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WITH RECURSIVE | |
unhex(str, val, weight) AS ( | |
SELECT 'deadbeef', 0, 1 | |
UNION ALL | |
SELECT | |
substr(str, 1, length(str) - 1), | |
val + (instr('0123456789ABCDEF', substr(str, length(str), 1)) - 1) * weight, | |
weight * 16 | |
FROM unhex WHERE length(str) > 0 | |
) | |
SELECT val FROM unhex order by weight desc limit 1; |
I have a table with hex timestamps as ids like this:
Id Name
015b2a63ec53 Alice
015b2aa24993 Boband I want to create a view which renders it like this:
Creation Date Name
2017-04-01 16:40:43 Alice
2017-04-01 17:48:50 BobYour approach is the only one I found which worked to convert the id. However, I wasn't able to create a working view for the whole table as my SQL skills are a little limited 😅
Maybe you can help me @ChiChou?
Utilizing ChatGPT-4 alongside this ChiChou snippet, I achieved a result akin to the following:
WITH
hexchars(key, value) AS (
VALUES
('0', 0),('1', 1),('2', 2),('3', 3),('4', 4),('5', 5),('6', 6),('7', 7),('8', 8),('9', 9),
('A', 10),('B', 11),('C', 12),('D', 13),('E', 14),('F', 15),
('a', 10),('b', 11),('c', 12),('d', 13),('e', 14),('f', 15)
),
-- Get all UUID from table
all_uuids AS (
SELECT uuid, replace(substr(uuid, 0, 14), '-', '') as hex_timestamp FROM podcasts_tts
)
-- Processing each UUID
SELECT
uu.uuid,
(
WITH RECURSIVE
-- Converting the part of timestamp hex to decimal
unhex(str, val, weight) AS (
SELECT uu.hex_timestamp, 0, 1
UNION ALL
SELECT
substr(str, 1, length(str) - 1),
val + (select value from hexchars where key = substr(str, length(str), 1)) * weight,
weight * 16
FROM unhex WHERE length(str) > 0
)
SELECT val FROM unhex ORDER BY weight DESC LIMIT 1
) AS decimal_timestamp
FROM
all_uuids uu;
It's a monster, but it works.
In my case, I have a column UUID v7 with has a timestamp inside, so I need to extract it with replace(substr(uuid, 0, 14), '-', '')
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Hi guys, Fantastic solution. I'm a super noob on SQL so pardon me if the question below is too obvious or too easy to do :
I was wondering if there's a way to process a long (a few millions of rows) table with a 64-bit Ids which string representation is stored in a field of type text ? I couldn't really pass that as a param to the CTE (as start value, instead of 'deadbeef' for example).
I am fully aware that I can write (a too easy) C function to do the job but I want to remain within SQL boundaries.
Thank you !