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  1. MariaDB Server
  2. MDEV-22224

Support JSON Path negative index

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    Description

      JSON Path allows to specify a negative array index, eg $[-1] returns the last element. This is not supported in MariaDB.

      Because of this, I believe there is no way to retrieve the last element without knowing the array length, nor to insert (JSON_ARRAY_INSERT()) an element at the end of the array. If I'm correct, this is a major missing feature for those who use JSON functions.

      MariaDB [test]> SELECT JSON_EXTRACT(JSON_ARRAY(1, 2, 3), '$[-1]');
      		 
      +--------------------------------------------+
      		 
      | JSON_EXTRACT(JSON_ARRAY(1, 2, 3), '$[-1]') |
      		 
      +--------------------------------------------+
      		 
      | NULL                                       |
      		 
      +--------------------------------------------+
      		 
      1 row in set, 1 warning (0.000 sec)
      		 
       
      		 
      Warning (Code 4042): Syntax error in JSON path in argument 2 to function 'json_extract' at position 3

      UPDATE: The task includes adding the negative index and the new keyword "last"

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          causes

          Bug - A problem which impairs or prevents the functions of the product. MDEV-28319 Assertion `cur_step->type & JSON_PATH_KEY' failed in json_find_path

          • Blocker - Blocks development and/or testing work, production could not run.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-29381 JSON paths containing dashes are reported as syntax errors in procedures

          • Critical - Crashes, loss of data, severe memory leak.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-29586 JSON_VALUE and JSON_EXTRACT doesn't handle special characters

          • Major - Major loss of function.
          • Closed
          is part of

          Task - A task that needs to be done. MDEV-28112 prepare 10.9.0 preview releases

          • Blocker - Blocks development and/or testing work, production could not run.
          • Closed
          relates to

          Bug - A problem which impairs or prevents the functions of the product. MDEV-27972 Unexpected behavior with negative zero (-0) in JSON Path

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-28350 Test failing on buildbot with UBSAN

          • Blocker - Blocks development and/or testing work, production could not run.
          • Closed

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            People

              rucha174 Rucha Deodhar
              f_razzoli Federico Razzoli
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              Dates

                Created:
                Updated:
                Resolved:

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