Updateing mysql json field in array - mysql

Question

Having this json:
{
f1: "abc",
f2: [
{id: 1, val:"a"},
{id: 2, val:"b"},
{id: 3, val:"c"}
],
f3: [
"a",
"b",
"c"
]
}
Update:
As an example:
SELECT JSON_SEARCH(
'{"f1": "abc", "f2": [{"id": "1", "val":"a"},{"id": "2", "2":"b"},{"id": 3, "val":"2"}], "f3": ["a","b","c"]}',
'all', '1', null, '$.f2[*].id');
returns the needed path for f2->id==1
I can then use
select json_set(
'{"f1": "abc", "f2": [{"id": "1", "val":"a"},{"id": "2", "2":"b"},{"id": 3, "val":"2"}], "f3": ["a","b","c"]}',
'$.f2[0].val', 'd');
to update the data.
but
SELECT JSON_SEARCH(
'{"f1": "abc", "f2": [{"id": 1, "val":"a"},{"id": "2", "2":"b"},{"id": 3, "val":"2"}], "f3": ["a","b","c"]}',
'all', '1', null, '$.f2[*].id');
won't find f2->id==1 . Neither does
SELECT JSON_SEARCH(
'{"f1": "abc", "f2": [{"id": 1, "val":"a"},{"id": "2", "2":"b"},{"id": 3, "val":"2"}], "f3": ["a","b","c"]}',
'all', 1, null, '$.f2[*].id');
=========
update 2:
I will just save the IDs as string... But right now i have onother problem:
SELECT JSON_SEARCH(
'{"mm": [{"id":"1","field":"test","value":33}]}',
'one', '1', null, '$.mm[*].id') as path;
is working
SELECT * FROM document_data where document_id=5;
update document_data set data=JSON_SET(data, '$.mm', json_array()) where document_id=5;
update document_data set data=JSON_ARRAY_APPEND(data, '$.mm', '{"id":"1","field":"test","value":33}') where document_id=5;
SELECT JSON_SEARCH(data, 'one', '1', null, '$.mm[*].id') as path from document_data where id='5';
is not working. Seems to be the quoting.
Can someone help?
==========
how can i update f2 where id==2 using JSON_SET?
Tried everything but i can't seem to figure out how to do it.
Many thanks
Rene

Answer 1

JSON_SEARCH, by design, seems to search only strings, see WL#7909: Server side JSON functions :: JSON_SEARCH.
One option, very unintuitive is to use something like (be careful with performance problems):
mysql> SELECT VERSION();
+-----------+
| VERSION() |
+-----------+
| 5.7.20 |
+-----------+
1 row in set (0.00 sec)
mysql> SET #`json` := '{
'> "f1": "abc",
'> "f2": [
'> {"id": 1, "val": "a"},
'> {"id": 2, "val": "b"},
'> {"id": 3, "val": "c"}
'> ],
'> "f3": ["a", "b", "c"]
'> }',
-> #`value` := 2,
-> #`base_path` := '$.f2';
Query OK, 0 rows affected (0.00 sec)
mysql> SELECT JSON_SEARCH(
-> REPLACE(
-> REPLACE(
-> REPLACE(
-> JSON_EXTRACT(#`json`, CONCAT(#`base_path`, '[*].id')),
-> ', ', '","'),
-> '[', '["'),
-> ']', '"]'),
-> 'one', #`value`) INTO #`path`;
Query OK, 1 row affected (0.00 sec)
mysql> SELECT #`path`;
+---------+
| #`path` |
+---------+
| "$[1]" |
+---------+
1 row in set (0.00 sec)
mysql> SELECT
-> CONCAT(
-> REPLACE(
-> JSON_UNQUOTE(#`path`),
-> '$',
-> #`base_path`
-> ),
-> '.val') INTO #`path`;
Query OK, 1 row affected (0.00 sec)
mysql> SELECT #`path`;
+-------------+
| #`path` |
+-------------+
| $.f2[1].val |
+-------------+
1 row in set (0.00 sec)
mysql> SELECT JSON_SET(#`json`, #`path`, 'd');
+-------------------------------------------------------------------------------------------------------------------+
| JSON_SET(#`json`, #`path`, 'd') |
+-------------------------------------------------------------------------------------------------------------------+
| {"f1": "abc", "f2": [{"id": 1, "val": "a"}, {"id": 2, "val": "d"}, {"id": 3, "val": "c"}], "f3": ["a", "b", "c"]} |
+-------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
See db-fiddle.