mysql - SQL 在不同的字节中拆分 hexastring

Question

我有一个 google bigquery 看起来像这样:

    #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

或者像这样

#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

结果表:

行时间戳 CAN_Frame 字节
1 2017-09-29 14:31:02 UTC S,48778,410,8, 84 10 00 25 00 21 00 4F 84 10 0025 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 0001 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 0027 00 08 00 03

或

行时间戳 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=

我的问题和问题现在是如何拆分 8 字节六角字符串，让我得到字符串的第 6 和第 7 个字节以 83 开头，第 8 个字节从 83 开始，第 3 个字节从 84 开始，第 4 个和第 4 个字节开始以 84 开头的字符串的第 5 个字节。这些数据对是我需要读取的 unsigned int 中具有 lsb msb 的值。

我希望有人能帮助我或至少理解我的问题。

最好的问候

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

结果是:

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

更新:

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

输出为

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