JSON_REMOVE object in MySQL - mysql

Question

I am trying to delete objects from my JSON array in MySQL.
I have a table called cart with two fields quote_id type int and items type json with the following row stored inside MySQL
quote_id: 0
items:
[
{
"a":42,
"b":"test4"
},
{
"a":32,
"b":"test3"
}
]
I am trying to create a query which would delete json objects from the json array. For example every
{
"a":32,
"b":"test3"
}
I have tried many queries. First I ended up with this:
UPDATE cart
SET items = IFNULL(JSON_REMOVE(items, JSON_UNQUOTE(JSON_SEARCH(items, 'one', 'test3'))), items)
WHERE quote_id = 13392;
However it just deletes "b":"test3" from the second object and left the "a":32 in it and I need a query that would find the whole object and would delete it.
This is my second query:
UPDATE cart
SET items = IFNULL(JSON_REMOVE(items, JSON_SEARCH(items, 'one', CAST('{"a": 32, "b": "test3"}' AS JSON))), items)
WHERE quote_id = 13392;
However I don't think the search on it works. I tried it without using the CAST()AS JSON, however it still did not work.
As I said I am pretty sure the problem is with the JSON_SEARCH, but maybe someone has the solution?
Thank you!

Answer 1

The JSON_SEARCH returns the path of the property, not the path to the object itself.
So you can use the following solution to get the object path with SUBSTR:
SELECT JSON_REMOVE(items,
SUBSTR(JSON_UNQUOTE(JSON_SEARCH(items, 'one', 'test3')), 1, LOCATE('.', JSON_UNQUOTE(JSON_SEARCH(items, 'one', 'test3')))-1)
) FROM cart
You can also use REGEXP_SUBSTR to get the object path:
SELECT JSON_REMOVE(items, REGEXP_SUBSTR(JSON_UNQUOTE(JSON_SEARCH(items, 'one', 'test3')), '^\\$\\[[0-9]+\\]'))
FROM cart
demo on dbfiddle.uk