Mysql Json Extract - wild card selection of key - mysql

Below is the json blob that I have in my database
{
RootData: {
202003: {
201903: {
"abc": 123,
xyz: 456
},
data1: {
},
data2: {
}
}
}
}
Right now I have a query where to pull the data inside the node 201903 as below
select blah blah,
JSON_EXTRACT(convert(columnname using utf8), '$.RootData."202003"."201903".abc') as blah
In the above query, my question revolve around the part '$.RootData."202003"."201903".abc'
I DO NOT want to hard code the part 201903 and looking for a syntax where it can select the node with help of wildcard's.
I tried the below options with no luck
'$.RootData."202003"."20*".abc'
'$.RootData."202003".[1].abc'
'$.RootData."202003".$.20*.abc'
Not working as it is not correct syntax I guess. Looking for right syntax. 20 is always start of that key, we can depend on that.
And it is the first key always.

Path in the form $.RootData."202003"**.abc should help.
Refer - https://www.db-fiddle.com/f/6g4qiekAU4i3J8iRoAZiCA/0
The result type will be array. To fetch the first match result, the result can be nested in another JSON_EXTRACT as below
select JSON_EXTRACT(JSON_EXTRACT(convert(data using utf8), '$.RootData."202003"**.abc'), '$[0]')
from rootdata;

Related

Is there a way to enrich JSON field in MySQL?

Let's take a simple schema with two tables, one that describes an simple entity item (id, name)
id | name
------------
1 | foo
2 | bar
and another, lets call it collection, that references to an item, but inside a JSON Object in something like
{
items: [
{
id: 1,
quantity: 2
}
]
}
I'm looking for a way to eventually enrich this field (kind of like populate in Mongo) in the collection with the item element referenced, to retrieve something like
{
...
items: [
{
item: {
id: 1,
name: foo
},
quantity: 2
}
]
...
}
If you have a solution with PostgreSQL, I take it as well.
If I understood correctly, your requirement is to convert an Input JSON data into MySQL table so that you can work with JSON but leverage the power of SQL.
Mysql8 recently released JSONTABLE function. By using this function, you can store your JSON in the table directly and then query it like any other SQL query.
It should serve your immediate case, but this means that your table schema will have a JSON column instead of traditional MySQL columns. You will need to check if it serves your purpose.
This is a good tutorial for the same.

How to construct a good Regex that matches all strings containing query for better performance in ElasticSearch?

Suppose I create an index in ElasticSearch by simply calling:
PUT strings
Then I insert documents by calling:
POST strings/string/<some_id>
{
"name": "some_string"
}
Now I want to search for all strings that contain the letter 's', for example:
GET strings/string
{
"query": {
"regexp": {
"name": ".*s.*"
}
}
}
Yes, this gives me what I want. However, I read from here that Matching everything like .* is very slow as well as using look-around regular expressions.
Question is, how should I construct the regex in order to do the same thing but with a better performance?

How do I query a complex JSONB field in Django 1.9

I have a table item with a field called data of type JSONB. I would like to query all items that have text that equals 'Super'. I am trying to do this currently by doing this:
Item.objects.filter(Q(data__areas__texts__text='Super'))
Django debug toolbar is reporting the query used for this is:
WHERE "item"."data" #> ARRAY['areas', 'texts', 'text'] = '"Super"'
But I'm not getting back any matching results. How can I query this using Django? If it's not possible in Django, then how can I query this in Postgresql?
Here's an example of the contents of the data field:
{
"areas": [
{
"texts": [
{
"text": "Super"
}
]
},
{
"texts": [
{
"text": "Duper"
}
]
}
]
}
try Item.objects.filter(data__areas__0__texts__0__text='Super')
it is not exact answer, but it can clarify some jsonb filter features, also read django docs
I am not sure what you want to achieve with this structure, but I was able to get the desired result only with strange raw query, it can look like this:
Item.objects.raw("SELECT id, data FROM (SELECT id, data, jsonb_array_elements(\"table_name\".\"data\" #> '{areas}') as areas_data from \"table_name\") foo WHERE areas_data #> '{texts}' #> '[{\"text\": \"Super\"}]'")
Dont forget to change table_name in query (in your case it should be yourappname_item).
Not sure you can use this query in real programs, but it probably can help you to find a way for a better solution.
Also, there is very good intro to jsonb query syntax
Hope it will help you

MariaDB COLUMN_JSON query returns binary

I've been trying to use dynamic columns with an instance of MariaDB v10.1.12.
First, I send the following query:
INSERT INTO savedDisplays (user, name, body, dataSource, params) VALUES ('Marty', 'Hey', 'Hoy', 'temp', COLUMN_CREATE('type', 'tab', 'col0', 'champions', 'col1', 'averageResults'));
Where params' type was defined as a blob, just like the documentation suggests.
The query is accepted, the table updated. If I COLUMN_CHECK the results, it tells me it's fine.
But when I try to select:
"SELECT COLUMN_JSON(params) AS params FROM savedDisplays;
I get a {type: "Buffer", data: Array} containing binary returned to me, instead of the {"type":"tab", "col0":"champions", "col1":"averageResults"} I expect.
EDIT: I can use COLUMN_GET just fine, but I need every column inside the params field, and I need to check the type property first to know what kind of and how many columns there are in the JSON / params field. I could probably make it work still, but that would require multiple queries, as opposed to only one.
Any ideas?
Try:
SELECT CONVERT(COLUMN_JSON(params) USING utf8) AS params FROM savedDisplays
In MariaDB 10 this works at every table:
SELECT CONVERT(COLUMN_JSON(COLUMN_CREATE('t', text, 'v', value)) USING utf8)
as json FROM test WHERE 1 AND value LIKE '%12345%' LIMIT 10;
output in node.js
[ TextRow { json: '{"t":"test text","v":"0.5339044212345805"}' } ]

Backand Query with geo point

I am trying to build a query, and pass parameters to it,
not sure how can I do it, here is my query
{ "object": "garages", "q": { "lat_long" : { "$within" : [[28.703341,77.130605],10000] } } }
I am passing lat,lng and radios.
Now I am able to pass the params, however in response I get lat_long
as "lat_long": "AAAAAAEBAAAAVYSbjCqfPEDyzTY3pkVTQA==" .
Is it encoded / serialized? How can I'll get my original values?
Thank you,
Point is stored as a binary value, in order to see your original values you have 2 option
You can manipulate the sql statement like this :
SELECT CONCAT(X(lat_long), ',', Y(lat_long)) as origin
FROM garages WHERE (ST_Distance ..........
but this way you want be able to edit the nosql tab
When you call REST API With 'GET' on object 'garages' you'll see the values as you oroginaly Posted them