SQL split hexastring in different bytes - mysql

Question

I've got a google bigquery looking like this:
#standardSQL
SELECT
timestamp,
CAN_Frame,
TRIM(SPLIT(CAN_Frame)[OFFSET(4)]) AS bytes
FROM
`data.source`
WHERE
LENGTH(CAN_Frame) > 1 and
SUBSTR(TRIM(SPLIT(CAN_Frame)[OFFSET(4)]),1,2) IN ('83', '84')
ORDER BY
timestamp DESC
LIMIT
8000
or like this
#standardSQL
SELECT
*
FROM (
SELECT
timestamp,
CAN_Frame,
REGEXP_EXTRACT(CAN_Frame, r', ([^,]+)$') AS bytes_string,
FROM_HEX(REPLACE(REGEXP_EXTRACT(CAN_Frame, r', ([^,]+)$'), ' ', '')) AS
bytes
FROM `data.source`
)
WHERE SUBSTR(bytes, 1, 1) IN (b'\x83', b'\x84')
ORDER BY timestamp DESC
LIMIT 8000
with the resulting tables:
Row timestamp CAN_Frame bytes
1 2017-09-29 14:31:02 UTC S,48778,410,8, 84 10 00 25 00 21 00 4F 84 10 00
25 00 21 00 4F
2 2017-09-29 14:30:42 UTC S,35847,480,8, 83 80 00 01 00 03 00 0D 83 80 00
01 00 03 00 0D
3 2017-09-29 14:30:40 UTC S,34612,4B2,8, 84 B2 00 27 00 08 00 03 84 B2 00
27 00 08 00 03
or
Row timestamp CAN_Frame bytes_string bytes
1 2017-09-29 14:31:02 UTC S,48778,410,8, 84 10 00 25 00 21 00 4F 84 10 00 25 00 21 00 4F hBAAJQAhAE8=
2 2017-09-29 14:30:42 UTC S,35847,480,8, 83 80 00 01 00 03 00 0D 83 80 00 01 00 03 00 0D g4AAAQADAA0=
3 2017-09-29 14:30:40 UTC S,34612,4B2,8, 84 B2 00 27 00 08 00 03 84 B2 00 27 00 08 00 03 hLIAJwAIAAM=
4 2017-09-29 14:30:39 UTC S,34314,4C0,8, 84 C0 00 1C 00 15 00 07 84 C0 00 1C 00 15 00 07 hMAAHAAVAAc=
My problem and question is now how to split the 8 byte hexa string in a way that let me have the 6th and 7th byte of string beginning with 83, the 8th byte from 83 and the 3rd byte from 84 and the 4th and 5th byte of the string beginning with 84. these datapairs are values with lsb msb in unsigned int that i need to read.
i hope somebody can help me or at least understand my problem.
best regards

Answer 1

#standardSQL
WITH `data.source` AS (
SELECT 'S,0,2B3,8, C2 B3 00 00 00 00 03 DE' AS frame UNION ALL
SELECT 'S,0,3FA,6, 00 E0 04 A5 00 0B' UNION ALL
SELECT 'S,0,440,8, 83 40 4E A5 00 47 00 64' UNION ALL
SELECT 'S,0,450,8, 84 50 01 12 01 19 01 B3' UNION ALL
SELECT 'S,0,4B0,8, 84 B0 4E A5 00 43 00 64'
)
SELECT
frame, bytes, STRING_AGG(b, ' ' ORDER BY p) AS selected_bytes
FROM (
SELECT frame, TRIM(SPLIT(frame)[OFFSET(4)]) AS bytes, SUBSTR(TRIM(SPLIT(frame)[OFFSET(4)]), 1, 2) AS f
FROM `data.source`
WHERE SUBSTR(TRIM(SPLIT(frame)[OFFSET(4)]), 1, 2) IN ('83', '84')
), UNNEST(SPLIT(bytes, ' ')) AS b WITH OFFSET AS p
WHERE CASE f WHEN '83' THEN p IN (5, 6, 7) WHEN '84' THEN p IN (2, 3, 4) END
GROUP BY frame, bytes
-- ORDER BY frame
result is:
frame bytes selected_bytes
S,0,440,8, 83 40 4E A5 00 47 00 64 83 40 4E A5 00 47 00 64 47 00 64
S,0,450,8, 84 50 01 12 01 19 01 B3 84 50 01 12 01 19 01 B3 01 12 01
S,0,4B0,8, 84 B0 4E A5 00 43 00 64 84 B0 4E A5 00 43 00 64 4E A5 00
Update for:
byte 6 and 7 from the string beginning with 83 called Aiout
one column contains byte 8 from the string beginning with 83 and byte 3 from the string beginning with 84 called Biout
one column contains byte 4 and 5 from the string beginning with 84 called Avout
Bvout containing byte 6 and 7 from the string beginning with 84
#standardSQL
WITH `data.source` AS (
SELECT 'S,0,2B3,8, C2 B3 00 00 00 00 03 DE' AS frame UNION ALL
SELECT 'S,0,3FA,6, 00 E0 04 A5 00 0B' UNION ALL
SELECT 'S,0,440,8, 83 40 4E A5 00 47 00 64' UNION ALL
SELECT 'S,0,450,8, 84 50 01 12 01 19 01 B3' UNION ALL
SELECT 'S,0,4B0,8, 84 B0 4E A5 00 43 00 64'
)
SELECT
frame, bytes,
STRING_AGG(CASE WHEN f='83' AND p IN (5, 6) THEN b ELSE '' END, ' ' ORDER BY p) AS Aiout,
STRING_AGG(CASE WHEN (f='83' AND p=7) OR (f='84' AND p=2) THEN b ELSE '' END, ' ' ORDER BY p) AS Biout,
STRING_AGG(CASE WHEN f='84' AND p IN (3, 4) THEN b ELSE '' END, ' ' ORDER BY p) AS Avout,
STRING_AGG(CASE WHEN f='84' AND p IN (5, 6) THEN b ELSE '' END, ' ' ORDER BY p) AS Bvout
FROM (
SELECT frame, TRIM(SPLIT(frame)[OFFSET(4)]) AS bytes, SUBSTR(TRIM(SPLIT(frame)[OFFSET(4)]), 1, 2) AS f
FROM `data.source`
WHERE SUBSTR(TRIM(SPLIT(frame)[OFFSET(4)]), 1, 2) IN ('83', '84')
), UNNEST(SPLIT(bytes, ' ')) AS b WITH OFFSET AS p
GROUP BY frame, bytes
ORDER BY frame
with output as
frame bytes Aiout Biout Avout Bvout
S,0,440,8, 83 40 4E A5 00 47 00 64 83 40 4E A5 00 47 00 64 47 00 64
S,0,450,8, 84 50 01 12 01 19 01 B3 84 50 01 12 01 19 01 B3 01 12 01 19 01
S,0,4B0,8, 84 B0 4E A5 00 43 00 64 84 B0 4E A5 00 43 00 64 4E A5 00 43 00