How to parse jsonb object in PostgreSql. The problem is - object every time is different by structure inside. Just like below.
{
"1":{
"1":{
"level":2,
"nodeType":2,
"id":2,
"parentNode":1,
"attribute_id":363698007,
"attribute_text":"Finding site",
"concept_id":386108004,
"description_text":"Heart tissue",
"hierarchy_id":0,
"description_id":-1,
"deeperCnt":0,
"default":false
},
"level":1,
"nodeType":1,
"id":1,
"parentNode":0,
"concept_id":22253000,
"description_id":37361011,
"description_text":"Pain",
"hierarchy_id":404684003,
"deeperCnt":1,
"default":false
},
"2":{
"1":{
"attribute_id":"363698007",
"attribute_text":"Finding site (attribute)",
"value_id":"321667001",
"value_text":"Respiratory tract structure (body structure)",
"default":true
},
"level":1,
"nodeType":1,
"id":3,
"parentNode":0,
"concept_id":11833005,
"description_id":20419011,
"description_text":"Dry cough",
"hierarchy_id":404684003,
"deeperCnt":1,
"default":false
},
"level":0,
"recAddedLevel":1,
"recAddedId":3,
"nodeType":0,
"multiple":false,
"currNodeId":3,
"id":0,
"lookForAttributes":false,
"deeperCnt":2,
}
So how should I parse all object and for example look if object inside has "attribute_id" = 363698007?
In this case we should get 'true' while selecting data rows in PostgreSql with WHERE statement.
2 question - what index should I use for jsonb column to get wanted results?
Already tried to create btree and gin indexes but even simple select returns 'null' with sql like this:
SELECT object::jsonb -> 'id' AS id
FROM table;
if I use this:
SELECT object
FROM table;
returns firstly described object.
The quick and dirty way (extended upon Collect Recursive JSON Keys In Postgres):
WITH RECURSIVE doc_key_and_value_recursive(id, key, value) AS (
SELECT
my_json.id,
t.key,
t.value
FROM my_json, jsonb_each(my_json.data) AS t
UNION ALL
SELECT
doc_key_and_value_recursive.id,
t.key,
t.value
FROM doc_key_and_value_recursive,
jsonb_each(CASE
WHEN jsonb_typeof(doc_key_and_value_recursive.value) <> 'object' THEN '{}'::jsonb
ELSE doc_key_and_value_recursive.value
END) AS t
)
SELECT t.id, t.data->'id' AS id
FROM doc_key_and_value_recursive AS c
INNER JOIN my_json AS t ON (t.id = c.id)
WHERE
jsonb_typeof(c.value) <> 'object'
AND c.key = 'attribute_id'
AND c.value = '363698007'::jsonb;
Online example: https://dbfiddle.uk/?rdbms=postgres_11&fiddle=57b7c4e817b2dd6580bbf28cbac10981
This may be improved a lot by stopping the recursion as soon as the relevant key and value are found, reverse sort and limit 1, aso. But it does the basic thing generically.
It also shows that jsonb->'id' does work as expected.
Related
There is a simple database entity:
case class Foo(id: Option[UUID], keywords: Seq[String])
I want to implement a search function which returns all entities of type Foo which have at least one keyword that contains the search string.
I'm using Slick and tried this:
def searchKeywords(txt: String): Future[Seq[Foo]] = {
val action = Foos.filter(p => p.keywords.any like s"%$txt%").result
db.run(action)
}
This piece of code compiles, but when executing, I get this SQL error:
PSQLException: ERROR: syntax error at or near "any"
The generated sql statement looks like:
select "id", "title", "tagline", "logo", "short_desc", "keywords", "initial_condition", "work_process", "end_result", "ts", "lm", "v" from "projects" where any("keywords") like '%foo%'
And it does not work with postgresql. (I'm using v12)
Schema for the table looks like this:
CREATE TABLE foos
(
id UUID NOT NULL PRIMARY KEY,
keywords varchar[] NOT NULL
);
How can I achieve to search in a list of strings using the like operator?
From a pure SQL point of view, you need a derived table to achieve that. I hope some expert corrects me if I'm wrong but you can't use SQL operator like on a array.
Supposing your table construction is :
CREATE TABLE foos
(
id UUID NOT NULL PRIMARY KEY,
keywords varchar[] NOT NULL
);
Then an SQL way of retrieving the results would be :
select * from (
select id, unnest(keywords) as keyw from foos
) myTable where keyw like '%foo%'
Otherwise, the syntax you're using for the like operator seems correct.
myProperty like s"%$myVariable"
We have foreign keys within a json blob in postgres. We join with these like so:
SELECT f.id, b.id FROM foo AS f
LEFT JOIN bar AS b ON f.data -> 'baz' ->> 'barId' = text(b.id)
I'm now trying out Hasura to do som graphql queries and I need these as object relationships. In the UI I can only try to manually add relationships with normal columns, not nested json data:
Is it at all possible to get a graphql relationship this way?
I got the answer in comments, thanks #iamnat. I'll just evolve here with my example for clarity since I still struggled a bit:
Super simple schema and data as such:
CREATE EXTENSION IF NOT EXISTS "uuid-ossp";
CREATE TABLE foo
(
id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
name text,
data jsonb NOT NULL
);
CREATE TABLE bar
(
id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
name text,
);
WITH bars AS (
INSERT INTO bar (name) VALUES ('bar') RETURNING id
)
INSERT INTO foo (name, data) VALUES ('foo', jsonb_build_object('barId', (SELECT id FROM bars)));
I then can create a function for the relationship:
CREATE FUNCTION foo_bar(foo_row foo)
RETURNS SETOF bar AS $$
SELECT *
FROM bar
WHERE text(id) = foo_row.data ->> 'barId'
$$ LANGUAGE sql STABLE;
This I can then use in Hasura as a computed field under "Data" -> foo -> Modify -> Computed fields -> "Add a new computed field". Just give it a name and reference the function in a dropdown:
I can then query:
query MyQuery {
foo {
name
foo_bar {
name
}
}
}
with expected result:
{
"data": {
"foo": [
{
"name": "foo",
"foo_bar": [
{
"name": "bar"
}
]
}
]
}
}
I have a many:many relationship between 2 tables: note and tag, and want to be able to search all notes by their tagId. Because of the many:many I have a junction table note_tag.
My goal is to expose a computed field on my Postgraphile-generated Graphql schema that I can query against, along with the other properties of the note table.
I'm playing around with postgraphile-plugin-connection-filter. This plugin makes it possible to filter by things like authorId (which would be 1:many), but I'm unable to figure out how to filter by a many:many. I have a computed column on my note table called tags, which is JSON. Is there a way to "look into" this json and pick out where id = 1?
Here is my computed column tags:
create or replace function note_tags(note note, tagid text)
returns jsonb as $$
select
json_strip_nulls(
json_agg(
json_build_object(
'title', tag.title,
'id', tag.id,
)
)
)::jsonb
from note
inner join note_tag on note_tag.tag_id = tagid and note_tag.note_id = note.id
left join note_tag nt on note.id = nt.note_id
left join tag on nt.tag_id = tag.id
where note.account_id = '1'
group by note.id, note.title;
$$ language sql stable;
as I understand the function above, I am returning jsonb, based on the tagid that was given (to the function): inner join note_tag on note_tag.tag_id = tagid. So why is the json not being filtered by id when the column gets computed?
I am trying to make a query like this:
query notesByTagId {
notes {
edges {
node {
title
id
tags(tagid: "1")
}
}
}
}
but right now when I execute this query, I get back stringified JSON in the tags field. However, all tags are included in the json, whether or not the note actually belongs to that tag or not.
For instance, this note with id = 1 should only have tags with id = 1 and id = 2. Right now it returns every tag in the database
{
"data": {
"notes": {
"edges": [
{
"node": {
"id": "1",
"tags": "[{\"id\":\"1\",\"title\":\"Psychology\"},{\"id\":\"2\",\"title\":\"Logic\"},{\"id\":\"3\",\"title\":\"Charisma\"}]",
...
The key factor with this computed column is that the JSON must include all tags that the note belongs to, even though we are searching for notes on a single tagid
here are my simplified tables...
note:
create table notes(
id text,
title text
)
tag:
create table tag(
id text,
title text
)
note_tag:
create table note_tag(
note_id text FK references note.id
tag_id text FK references tag.id
)
Update
I am changing up the approach a bit, and am toying with the following function:
create or replace function note_tags(n note)
returns setof tag as $$
select tag.*
from tag
inner join note_tag on (note_tag.tag_id = tag.id)
where note_tag.note_id = n.id;
$$ language sql stable;
I am able to retrieve all notes with the tags field populated, but now I need to be able to filter out the notes that don't belong to a particular tag, while still retaining all of the tags that belong to a given note.
So the question remains the same as above: how do we filter a table based on a related table's PK?
After a while of digging, I think I've come across a good approach. Based on this response, I have made a function that returns all notes by a given tagid.
Here it is:
create or replace function all_notes_with_tag_id(tagid text)
returns setof note as $$
select distinct note.*
from tag
inner join note_tag on (note_tag.tag_id = tag.id)
inner join note on (note_tag.note_id = note.id)
where tag.id = tagid;
$$ language sql stable;
The error in approach was to expect the computed column to do all of the work, whereas its only job should be to get all of the data. This function all_nuggets_with_bucket_id can now be called directly in graphql like so:
query MyQuery($tagid: String!) {
allNotesWithTagId(tagid: $tagid) {
edges {
node {
id
title
tags {
edges {
node {
id
title
}
}
}
}
}
}
}
A simple example, I have a select sql:
select
t.id,
t.name,
null as grade
t.class,
t.no
from table t
and I execute this sql by sequelize.query(), the result of it returned is wrong:
all the field after grade like class is null.
But I move these fields above the grade, I can get the real value of these fields by sequelize.query()
Check your relation definition ex:
Model.hasOne(db.RelatedModel, {
as: 'namedAlias',
foreignKey: 'id' // <- Make sure you add the relation id as the foreign key
})
I have this query;
knex('metrics').insert(function() {
this.select('metric as name')
.from('stage.metrics as s')
.whereNotExists(function() {
this.select('*')
.from('metrics')
.where('metrics.name', knex.raw('s.metric'))
})
})
The table metrics has two columns; an id, which is incrementing, and name. I expected this to insert into the name column because the subquery has one column, labeled name, and default id. however, instead it complains that I am providing a column of type character varying for my integer column id. How do I make it explicit that I want the id to take the default value?
This can do the trick
knex('metrics').insert(function() {
this
.select([
knex.raw('null::bigint as id'), // or any other type you need (to force using default value you need to pass explicitly null value to insert query)
'metric as name'
])
.from('stage.metrics as s')
.whereNotExists(function() {
this.select('*')
.from('metrics')
.where('metrics.name', knex.raw('s.metric'))
})
})
I know, looks a bit hacky. Would be great to see something in knex API like (example below is a proposal and not a working example)
knex('table_name')
.insert(
['name', 'surname'],
function () {
this.select(['name', 'surname']).from('other_table'))
}
)
Which produces
insert into table_name (name, surname) select name, surname from other_table;
I'm not sure about this interface, but you got the point. Like explicitly write fields you want to insert.