JSON.ARRTRIM - Amazon MemoryDB for Redis
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JSON.ARRTRIM

Trim arrays at the path so that it becomes subarray [start, end], both inclusive.

  • If the array is empty, do nothing, return 0.

  • If start <0, treat it as 0.

  • If end >= size (size of the array), treat it as size-1.

  • If start >= size or start > end, empty the array and return 0.

Syntax

JSON.ARRINSERT <key> <path> <start> <end>

  • key (required) – Redis key of JSON document type

  • path (required) – a JSON path

  • start (required) – start index, inclusive.

  • end (required) – end index, inclusive.

Return

If the path is enhanced syntax:

  • Array of integers, representing the new length of the array at each path.

  • If a value is an empty array, its corresponding return value is null.

  • If a value is not an array, its corresponding return value is null.

  • OUTOFBOUNDARIES error if an index argument is out of bounds.

If the path is restricted syntax:

  • Integer, the new length of the array.

  • Null if the array is empty.

  • WRONGTYPE error if the value at the path is not an array.

  • OUTOFBOUNDARIES error if an index argument is out of bounds.

Examples

Enhanced path syntax:

127.0.0.1:6379> JSON.SET k1 . '[[], ["a"], ["a", "b"], ["a", "b", "c"]]'
OK
127.0.0.1:6379> JSON.ARRTRIM k1 $[*] 0 1
1) (integer) 0
2) (integer) 1
3) (integer) 2
4) (integer) 2
   127.0.0.1:6379> JSON.GET k1
   "[[],[\"a\"],[\"a\",\"b\"],[\"a\",\"b\"]]"

Restricted path syntax:

127.0.0.1:6379> JSON.SET k1 . '{"children": ["John", "Jack", "Tom", "Bob", "Mike"]}'
OK
127.0.0.1:6379> JSON.ARRTRIM k1 .children 0 1
(integer) 2
127.0.0.1:6379> JSON.GET k1 .children
"[\"John\",\"Jack\"]"