My Postgres DB Table BookingDetails has columns - id(bigint), info(jsonb)
My Json structure:
"bookingType": “special”,
“travellers”: [
{
"id": 1,
"nationality": "SomeValue",
}
],
“someTag”: “abc”
}
The travellers here is an array (and in this example, there’s only one element)
I want to:
Select records where nationality=‘CertainValue’
Update records set nationality=‘AnotherValue’ where nationality=‘CertainValue’
I could retrieve the array using:
select CAST (info->'travellers' AS TEXT) from BookingDetails
[
{
"id": 1,
"nationality": "SomeValue",
}
]
I could retrieve the array first element using:
select CAST (info->'travellers'->>0 AS TEXT) from BookingDetails
{
"id": 1,
"nationality": "SomeValue"
}
But how to do a select based on nationality=‘CertainValue’?
try this :
SELECT jsonb_set(info, array['travellers', (a.id - 1) :: text, 'nationality'], to_jsonb('AnotherValue' :: text))
FROM BookingDetails
CROSS JOIN LATERAL jsonb_array_elements(info->'travellers') WITH ORDINALITY AS a(content, id)
WHERE a.content->>'nationality' = 'CertainValue'
see the test result in dbfiddle
Related
I want to remove a JSONB object by their unique 'id' value from a JSONB array. I am no expert at writing SQL code, but I managed to write the concatenate function.
For an example: Remove this object from an array below.
{
"id": "ad26e2be-19fd-4862-8f84-f2f9c87b582e",
"title": "Wikipedia",
"links": [
"https://en.wikipedia.org/1",
"https://en.wikipedia.org/2"
]
},
Schema:
CREATE TABLE users (
url text not null,
user_id SERIAL PRIMARY KEY,
name VARCHAR,
list_of_links jsonb default '[]'
);
list_of_links format:
[
{
"id": "ad26e2be-19fd-4862-8f84-f2f9c87b582e",
"title": "Wikipedia",
"links": [
"https://en.wikipedia.org/1",
"https://en.wikipedia.org/2"
]
},
{
"id": "451ac172-b93e-4158-8e53-8e9031cfbe72",
"title": "Russian Wikipedia",
"links": [
"https://ru.wikipedia.org/wiki/",
"https://ru.wikipedia.org/wiki/"
]
},
{
"id": "818b99c8-479b-4846-ac15-4b2832ec63b5",
"title": "German Wikipedia",
"links": [
"https://de.wikipedia.org/any",
"https://de.wikipedia.org/any"
]
},
...
]
The concatenate function:
update users set list_of_links=(
list_of_links || (select *
from jsonb_array_elements(list_of_links)
where value->>'id'='ad26e2be-19fd-4862-8f84-f2f9c87b582e'
)
)
where url='test'
returning *
;
Your json data is structured so you have to unpack it, operate on the unpacked data, and then repack it again:
SELECT u.url, u.user_id, u.name,
jsonb_agg(
jsonb_build_object('id', l.id, 'title', l.title, 'links', l.links)
) as list_of_links
FROM users u
CROSS JOIN LATERAL jsonb_to_recordset(u.list_of_links) AS l(id uuid, title text, links jsonb)
WHERE l.id != 'ad26e2be-19fd-4862-8f84-f2f9c87b582e'::uuid
GROUP BY 1, 2, 3
The function jsonb_to_recordset is a set-returning function so you have to use it as a row source, joined to its originating table with the LATERAL clause so that the list_of_links column is available to the function to be unpacked. Then you can delete the records you are not interested in using the WHERE clause, and finally repack the structure by building the record fields into a jsonb structure and then aggregating the individual records back into an array.
I wrote this on JS but that does not matter to how it works. Essentially, its getting all the items from the array, then finding the matching id which returns an index. And using that index, I use "-" operator which takes the index and removes it from the array. Sorry if my grammar is bad.
//req.body is this JSON object
//{"url":"test", "id": "ad26e2be-19fd-4862-8f84-f2f9c87b582e"}
var { url, id } = req.body;
pgPool.query(
`
select list_of_links
from users
where url=$1;
`,
[url],
(error, result) => {
//block code executing further if error is true
if (error) {
res.json({ status: "failed" });
return;
}
if (result) {
// this function just returns the index of the array element where the id matches from request's id
// 0, 1, 2, 3, 4, 5
var index_of_the_item = result.rows.list_of_links
.map(({ id: db_id }, index) =>
db_id === id ? index : false
)
.filter((x) => x !== false)[0];
//remove the array element by it's index
pgPool.query(
`
update users
set list_of_links=(
list_of_links - $1::int
)
where url=$2
;
`,
[index_of_the_item, url], (e, r) => {...}
);
}
}
);
I have a jsonB field in postgresql DB table, it has data like this
{
"units": [
{
"id": 299872379221376,
"unitNumber": "1",
"unitFloorSpace": 1,
"createdTimeStamp": 1587994498586
},
{
"id": 299872417011074,
"unitNumber": "2",
"unitFloorSpace": 2,
"createdTimeStamp": 1588001330085
}
]
}
I just want to list all unitNumbers like below, what would be the query for that?
1,
2,
I have tried below json query but that doesn’t list
Select form_data -> units -> unitNumbers from table where row_id =1;
here is one way:
select jsonb_array_elements(jsonb_extract_path(jdata,'units')) ->> 'unitNumber' as UnitNumber
from tableName;
db<>fiddle here
I have a table in the data base which has a column texts of type jsonb which looks like:
{
"texts": [
{
"locale": "ar",
"textDictionary": {
"key1": "arabic1",
"key2": "arabic2"
}
},
{
"locale": "en",
"textDictionary": {
"key1": "english1",
"key2": "english2"
}
}
]
}
Given the structure above, the goal is to convert this column to use a map of locales to dictionary instead of an array of locales, this is in order to support indexing the tsvector by locale in a more decent way like this:
CREATE INDEX texts_index ON docs
USING gin ( to_tsvector('english',texts->'en') );
Desired structure:
{
"ar": {
"key1": "arabic1",
"key2": "arabic2"
},
"en": {
"key1": "english1",
"key2": "english2"
}
}
Any advice would be great! Thank you very much! - Is there anyway doing that in PostgreSQL, or should this be done in the application level?
You can convert this by unnesting and aggregating back:
select id, jsonb_object_agg(x.e ->> 'locale', x.e -> 'textDictionary')
from data d
cross join jsonb_array_elements(d.texts -> 'texts') as x(e)
group by id;
This can be used for an UPDATE statement:
update data
set texts = t.new_texts
from (
select id, jsonb_object_agg(x.e ->> 'locale', x.e -> 'textDictionary') as new_texts
from data d
cross join jsonb_array_elements(d.texts -> 'texts') as x(e)
group by id
) t
where t.id = data.id;
You can try this:
update docs
set texts= (
select jsonb_object_agg(j->>'locale',j->'textDictionary')
from
jsonb_array_elements(texts->'texts') j
)
DEMO
I have a jsonb column in my table and data is in this format:
[
{
"id": 1,
"DATA": {
"a": "XXX",
"key": "value1"
}
},
{
"id": 2,
"DATA": {
"a": "XXX",
"key": "value2"
}
}
]
I would like to get the count of rows in which key = value1. I tried some queries like:
select count(t.id)
from my_table t,
jsonb_array_elements(summary->'DATA') elem
where elem->>'key' = 'value1';
It returned 0 rows, though there are rows in db with that key value pair. Thanks in advance,
Use jsonb_array_elements() for the column summary as it is in the form of json array.
select count(distinct t.id)
from my_table t
cross join jsonb_array_elements(summary) elem
where elem->'DATA'->>'key' = 'value1';
Alternatively, you can get rid of the function using #> operator:
select count(t.id)
from my_table t
where summary #> '[{"DATA":{"key":"value1"}}]'
The second solution should be faster.
Db<>fiddle.
Given this dataset:
[
{
"dataChannelId": 8516,
"measures": [
{
"dateTime": "2019-01-01T12:00:00",
},
{
"dateTime": "2019-01-02T12:00:00",
}
}]
And this query:
WITH
temp AS
(
SELECT
dataChannelId,
arrayElement.ArrayValue as element
FROM GriegInputStream
CROSS APPLY GetArrayElements([mesurasdfes]) AS arrayElement
)
SELECT
temp.dataChannelId as sensorId, temp.element.dateTime, temp.element.value,temp.element.unit,temp.element.maxValue, temp.element.minValue
INTO
Sensoroutput
FROM
temp
I get invalid column name, does not exist on dataChannelId, but measures seem to work fine. How can I access this value without stream analytics complaining?
Your sample json data lack a square bracket ].
sample data:
[
{
"dataChannelId": 8516,
"measures": [
{
"dateTime": "2019-01-01T12:00:00",
},
{
"dateTime": "2019-01-02T12:00:00",
}
]
}
]
Query sql:
WITH
temp AS
(
SELECT
jsoninput.dataChannelId,
arrayElement.ArrayValue as element
FROM jsoninput
CROSS APPLY GetArrayElements(jsoninput.measures) AS arrayElement
)
SELECT
temp.dataChannelId as sensorId, temp.element.dateTime
INTO
Sensoroutput
FROM
temp
Output: