Search for a value in a JSON field in MYSQL - mysql

I am trying to understand the "new" MYSQL JSON field.
I have this table:
id (int-11, not_null, auto_inc)
customer_id (int-11, not null)
labels (json)
With this data:
id: 1
customer_id: 1
labels: [{"isnew": "no", "tagname": "FOO", "category": "CAT_1", "isdeleted": "no"}, {"isnew": "yes", "tagname": "BAR", "category": "CAT_2", "isdeleted": "no"}]
JSON beautify
[
{
"tagname": "FOO",
"category": "CAT_1",
"isnew": "no",
"isdeleted": "no"
},
{
"tagname": "BAR",
"category": "CAT_2",
"isnew": "yes",
"isdeleted": "no"
}
]
And now I want to SELECT all the customers (by customer_id) in the table that have a specific category and a specific tagname
I tried this one:
SELECT * FROM labels_customers_json
WHERE JSON_SEARCH(labels, 'all', 'BAR') IS NOT NULL
But this is not what I want. This one is searching in every json attribute.
I have seen some examples of JSON_EXTRACT:
SELECT * FROM `e_store`.`products`
WHERE
`category_id` = 1
AND JSON_EXTRACT(`attributes` , '$.ports.usb') > 0
AND JSON_EXTRACT(`attributes` , '$.ports.hdmi') > 0;
SELECT c, c->"$.id", g, n
FROM jemp
WHERE JSON_EXTRACT(c, "$.id") > 1
ORDER BY c->"$.name";
So I tried this
SELECT * FROM labels_customers_json
WHERE JSON_EXTRACT(labels, '$.tagname') = 'BAR'
SELECT labels, JSON_EXTRACT(labels, "$.customer_id"), customer_id
FROM labels_customers_json
WHERE JSON_EXTRACT(labels, "$.customer_id") > 0

You could probably try using SELECT * FROM labels_customers_json WHERE JSON_SEARCH(labels, 'all', "BAR", NULL, "$[*].tagname") is not null - although i cannot say if that is the best way to perform this query.

You can use JSON_SEARCH to search on a specific path too. So you can use the following query:
SELECT *
FROM labels_customers_json
WHERE JSON_SEARCH(labels, 'all', 'BAR', NULL, '$[*].tagname') IS NOT NULL
You can also use JSON_EXTRACT and JSON_CONTAINS together:
SELECT *
FROM labels_customers_json
WHERE JSON_CONTAINS(JSON_EXTRACT(labels, '$[*].tagname'), '["BAR"]') > 0;
You can also use only JSON_CONTAINS to check:
SELECT *
FROM labels_customers_json
WHERE JSON_CONTAINS(labels, '{"tagname":"BAR"}') > 0;
demos: https://www.db-fiddle.com/f/rufrThAQPfXHrK9YyibFSm/2

Related

How to get a specific object in an JSON array in MySQL?

I have a JSON column "jobs" that looks like this:
[
{
"id": "1",
"done": "100",
"target": "100",
"startDate": "123123132",
"lastAction": "123123132",
"status": "0"
},
{
"id": "2",
"done": "10",
"target": "20",
"startDate": "2312321",
"lastAction": "2312321",
"status": "1"
}
]
I want to filter the array by object key values. For example: To find all items that have target > done, status != 0 and lastAction is yesterday to get response like this:
[
{
"id": "1",
"done": "19",
"target": "100",
"startDate": "123123132",
"lastAction": "123123132",
"status": "0"
}
]
I know I can extract the data to a JSON_TABLE() to do the filtering but I don't get the original object back(unless I recreate it back) and the solution is not dynamic.
Can this kind of array filtering can really be done in MySQL?
SELECT JSON_PRETTY(JSON_EXTRACT(jobs.jobs, CONCAT('$[', j.rownum-1, ']'))) AS object
FROM jobs
CROSS JOIN JSON_TABLE(
jobs.jobs, '$[*]' COLUMNS(
rownum for ordinality,
done int path '$.done',
target int path '$.target',
status int path '$.status'
)
) as j
WHERE j.target > j.done AND j.status != 0;
You also mentioned a condition on lastAction, but the example values you gave are not valid dates, so I'll leave that enhancement to you. The example above demonstrates the technique.
Yes it is possible to do it using the JSON_EXTRACT and JSON_SEARCH functions.
Let's say your table is named tbl_Jobs and the jobs column is of type JSON.
SELECT * FROM tbl_Jobs
WHERE JSON_EXTRACT(jobs, "$[*].target") = JSON_EXTRACT(jobs, "$[*].done")
AND JSON_EXTRACT(jobs, "$[*].status") != 0
AND JSON_SEARCH(jobs, 'one', DATE_SUB(CURDATE(), INTERVAL 1 DAY), NULL, "$[*].lastAction") IS NOT NULL

How to map nested array items with N1QL?

I have documents in a bucket called blocks in the following format:
{
"random_field": 1,
"transactions": [{
"id": "CCCCC",
"inputs": [{
"tx_id": "AAAAA",
"index": 0
},{
"tx_id": "BBBBB",
"index": 1
}]
}]
}
{
"transactions": [{
"id": "AAAAA",
"outputs": [{
"field1": "value123",
"field2": "value456"
},{
"field1": "ignore",
"field2": "ignore"
}]
}]
}
{
"transactions": [{
"id": "BBBBB",
"outputs": [{
"field1": "ignored",
"field2": "ignored"
},{
"field1": "value999",
"field2": "value888"
}]
}]
}
and I need to map the inputs from the first document to the corresponding outputs of the second and third documents. The way to do it manually is to, for each input, find a transaction with id equal to the input's tx_id, and then get the item from the outputs array based on the index of the input. To exemplify, this is the object I would like to return in this scenario:
{
"random_field": 1,
"transactions": [{
"id": "CCCCC",
"inputs": [{
"tx_id": "AAAAA",
"index": 0,
"output": {
"field1": "value123",
"field2": "value456"
}
},{
"tx_id": "BBBBB",
"index": 1,
"output": {
"field1": "value999",
"field2": "value888"
}
}]
}]
}
I managed to come up with the following query:
SELECT b.random_field,
b.transactions -- how to map this?
FROM blocks b
UNNEST b.transactions t
UNNEST t.inputs input
JOIN blocks `source` ON (ANY tx IN `source`.transactions SATISFIES tx.`id` = input.tx_id END)
UNNEST `source`.transactions source_tx
UNNEST source_tx.outputs o
WHERE (ANY tx IN b.transactions SATISFIES tx.`id` = 'AAAAA' END) LIMIT 1;
I suppose there should be a way to map b.transactions.inputs by using source_tx.outputs, but I couldn't find how.
I came across this other answer, but I don't really understand how it applies to my scenario. Maybe it does, but I am very new to Couchbase, so I am very much lost: How to map array values in one document to another and display in result
Basically you want inline some other document into current document using condition.
Instead of JOINs+ GROUPS use subquery expressions + correlated subqueries. (b.*, "abc" AS transactions, selects all fields of b and adds transactions (if already exist overwrite else adds)
CREATE INDEX ix1 ON blocks (ALL ARRAY FOR ot.id FOR ot IN transactions END);
SELECT b.*,
(SELECT t.*,
(SELECT i.*,
(SELECT RAW ot
FROM blocks AS o
UNNEST o.transactions AS ot
UNNEST ot.outputs AS oto
WHERE i.tx_id = ot.id AND i.`index` = UNNEST_POS(oto))[0] AS output
FROM t.`inputs` AS i) AS inputs
FROM b.transactions AS t) AS transactions
FROM blocks AS b
WHERE ANY tx IN b.transactions SATISFIES tx.`inputs` IS NOT NULL END ;
OR
SELECT b.*,
(SELECT t.*,
(SELECT i.*,
(SELECT RAW ot.outputs[i.`index`]
FROM blocks AS o
UNNEST o.transactions AS ot
WHERE i.tx_id = ot.id
LIMIT 1)[0] AS output
FROM t.`inputs` AS i) AS inputs
FROM b.transactions AS t) AS transactions
FROM blocks AS b
WHERE ANY tx IN b.transactions SATISFIES tx.`inputs` IS NOT NULL END ;

How to deal with not existing values using JSON_EXTRACT?

I have a list ob objects. Each object contains several properties. Now I want to make a SELECT statement that gives me a list of a single property values. The simplified list look like this:
[
[
{
"day": "2021-10-01",
"entries": [
{
"name": "Start of competition",
"startTimeDelta": "08:30:00"
}
]
},
{
"day": "2021-10-02",
"entries": [
{
"name": "Start of competition",
"startTimeDelta": "03:30:00"
}
]
},
{
"day": "2021-10-03",
"entries": [
{
"name": "Start of competition"
}
]
}
]
]
The working SELECT is now
SELECT
JSON_EXTRACT(column, '$.days[*].entries[0].startTimeDelta') AS list
FROM table
The returned result is
[
"08:30:00",
"03:30:00"
]
But what I want to get (and also have expected) is
[
"08:30:00",
"03:30:00",
null
]
What can I do or how can I change the SELECT statement so that I also get NULL values in the list?
SELECT startTimeDelta
FROM test
CROSS JOIN JSON_TABLE(val,
'$[*][*].entries[*]' COLUMNS (startTimeDelta TIME PATH '$.startTimeDelta')) jsontable
https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=491f0f978d200a8a8522e3200509460e
Do you also have a working idea for MySQL< 8? – Lars
What is max amount of objects in the array on the 2nd level? – Akina
Well it's usually less than 10 – Lars
SELECT JSON_EXTRACT(val, CONCAT('$[0][', num, '].entries[0].startTimeDelta')) startTimeDelta
FROM test
-- up to 4 - increase if needed
CROSS JOIN (SELECT 0 num UNION SELECT 1 UNION SELECT 2 UNION SELECT 3) nums
WHERE JSON_EXTRACT(val, CONCAT('$[0][', num, '].entries[0]')) IS NOT NULL;
https://www.db-fiddle.com/f/xnCCSTGQXevcpfPH1GAbUo/0

Find price greater than using JSON operators

Json:
"availability": [
{
"qty": 25,
"price": 3599,
"is_available": true
},
{
"qty": 72,
"price": 3599,
},
"is_available": true
]
If I want to find price with value = "3599" I use this query:
select *
from product
where to_tsvector(product.data #>> '{availability}') ## to_tsquery('3599')
or this query:
SELECT *
FROM product
WHERE product.data #> '{"availability": [ { "price": 3599} ] }';
Nice. It's work fine.
But I need also to find price > 1000
I try this:
select *
from product
where to_tsvector(product.data #>> '{availability}') ## to_tsquery('>1000')
But the result is empty (nothing found).
Full text search is the wrong tool for this kind of queries.
With Postgres 12, you can use a JSON/Path expression:
select *
from product
where data ## '$.availability[*].price > 100';
For older Postgres versions you need to unnest the array:
select *
from product
where exists (select *
from jsonb_array_elements(data -> 'availability') as x(item)
where (x.item ->> 'price')::int > 100);

Full text search in concrete node in json

I has table "Product" with two columns:
Id - Bigint primary key
data - Jsonb
Here example of json:
{
"availability": [
{
"qty": 10,
"price": 42511,
"store": {
"name": "my_best_store",
"hours": null,
"title": {
"en": null
},
"coords": null,
"address": null,
I insert json to column "data".
Here sql get find "my_best_store"
select *
from product
where to_tsvector(product.data) ## to_tsquery('my_best_store')
Nice. It's work fine.
But I need to find "my_best_store" only in section "availability".
I try this but result is empty:
select *
from product
where to_tsvector(product.data) ## to_tsquery('availability & my_best_store')
Assuming you want to search in the name attribute, you can do the following:
select p.*
from product p
where exists (select *
from jsonb_array_elements(p.data -> 'availability') as t(item)
where to_tsvector(t.item -> 'store' ->> 'name') ## to_tsquery('my_best_store'))
With Postgres 12, you can simplify that to:
select p.*
from product p
where to_tsvector(jsonb_path_query_array(data, '$.availability[*].store.name')) ## to_tsquery('my_best_store')