I'm struggling to find the right syntax for updating an array in a jsonb column in postgres 9.6.6
Given a column "comments", with this example:
[
{
"Comment": "A",
"LastModified": "1527579949"
},
{
"Comment": "B",
"LastModified": "1528579949"
},
{
"Comment": "C",
"LastModified": "1529579949"
}
]
If I wanted to append Z to each comment (giving AZ, BZ, CZ).
I know I need to use something like jsonb_set(comments, '{"Comment"}',
Any hints on finishing this off?
Thanks.
Try:
UPDATE elbat
SET comments = array_to_json(ARRAY(SELECT jsonb_set(x.original_comment,
'{Comment}',
concat('"',
x.original_comment->>'Comment',
'Z"')::jsonb)
FROM (SELECT jsonb_array_elements(elbat.comments) original_comment) x))::jsonb;
It uses jsonb_array_elements() to get the array elements as set, applies the changes on them using jsonb_set(), transforms this to an array and back to json with array_to_json().
But that's an awful lot of work. OK, maybe there is a more elegant solution, that I didn't find. But since your JSON seems to have a fixed schema anyway, I'd recommend a redesign to do it the relational way and have a simple table for the comments plus a linking table for the objects the comment is on. The change would have been very, very easy in such a model for sure.
Find a query returning the expected result:
select jsonb_agg(value || jsonb_build_object('Comment', value->>'Comment' || 'Z'))
from my_table
cross join jsonb_array_elements(comments);
jsonb_agg
-----------------------------------------------------------------------------------------------------------------------------------------------------
[{"Comment": "AZ", "LastModified": "1527579949"}, {"Comment": "BZ", "LastModified": "1528579949"}, {"Comment": "CZ", "LastModified": "1529579949"}]
(1 row)
Create a simple SQL function based of the above query:
create or replace function update_comments(jsonb)
returns jsonb language sql as $$
select jsonb_agg(value || jsonb_build_object('Comment', value->>'Comment' || 'Z'))
from jsonb_array_elements($1)
$$;
Use the function:
update my_table
set comments = update_comments(comments);
DbFiddle.
Related
For simplicity, a row of table looks like this:
key: "z06khw1bwi886r18k1m7d66bi67yqlns",
reference_keys: {
"KEY": "1x6t4y",
"CODE": "IT137-521e9204-ABC-TESTE"
"NAME": "A"
},
I have a jsonb object like this one {"KEY": "1x6t4y", "CODE": "IT137-521e9204-ABC-TESTE", "NAME": "A"} and I want to search for a query in the values of any key. If my query is something like '521e9204' I want it to return the row that reference_keys has '521e9204' in any value. Basicly the keys don't matter for this scenario.
Note: The column reference_keys and so the jsonb object, are always a 1 dimensional array.
I have tried a query like this:
SELECT * FROM table
LEFT JOIN jsonb_each_text(table.reference_keys) AS j(k, value) ON true
WHERE j.value LIKE '%521e9204%'
The problem is that it duplicates rows, for every key in the json and it messes up the returned items.
I have also thinked of doing something like this:
SELECT DISTINCT jsonb_object_keys(reference_keys) from table;
and then use a query like:
SELECT * FROM table
WHERE reference_keys->>'CODE' like '%521e9204%'
It seems like this would work but I really don't want to rely on this solution.
You can rewrite your JOIN to an EXISTS condition to avoid the duplicates:
SELECT t.*
FROM the_table t
WHERE EXISTS (select *
from jsonb_each_text(t.reference_keys) AS j(k, value)
WHERE j.value LIKE '%521e9204%');
If you are using Postgres 12 or later, you can also use a JSON path query:
where jsonb_path_exists(reference_keys, 'strict $.** ? (# like_regex "521e9204")')
I am looking to translate an SQL query (Postgres) into Scala Slick code for use in my Play application.
The data looks something like this:
parent_id | json_column
----------+-----------------------------------------
| [ {"id": "abcde-12345", "data": "..."}
2 | , {"id": "67890-fghij", "data": "..."}
| , {"id": "klmno-00000", "data": "..."} ]
Here's my query in PostgreSQL:
SELECT * FROM table1
WHERE id IN (
SELECT id
FROM
table1 t1,
json_array_elements(t1.json_column) e,
json_to_record(e.value) AS r("id" text, data text)
WHERE
"id" = 'abcde-12345'
AND t1.parent_id = 2
);
This finds the results I need; any objects in t1 that include a "row" in the json_column array that has the id of "abcde-12345". The "parent_id" and "id" will be passed in to this query via query parameters (both Strings).
How would I write this query in Scala using Slick?
The easiest - maybe laziest? - way is probably to just use plain sql ..
sql"""[query]""".as[ (type1,type2..) ]
using the $var notation for the variables.
Otherwise you can use SimpleFunction to map the json calls, but I'm not quite sure how that works when they generate multiple results per row. Seems that might get complicated..
I have below json string in my table column which is of type jsonb,
{
"abc": 1,
"def": 2
}
i want to remove the "abc" key from it and insert "mno" with some default value. i followed the below approcach for it.
UPDATE books SET books_desc = books_desc - 'abc';
UPDATE books SET books_desc = jsonb_set(books_desc, '{mno}', '5');
and it works.
Now i have another table with json as below,
{
"a": {
"abc": 1,
"def": 2
},
"b": {
"abc": 1,
"def": 2
}
}
Even in this json, i want to do the same thing. take out "abc" and introduce "mno" with some default value. Please help me to achieve this.
The keys "a" and "b" are dynamic and can change. But the values for "a" and "b" will always have same keys but values may change.
I need a generic logic.
Requirement 2:
abc:true should get converted to xyz:1.
abc:false should get converted to xyz:0.
demo:db<>fiddle
Because of a possible variety of your JSON keys it might be complicated to generate a common query. This is because you need to give the path within the json_set() function. But without actual values it would be hard.
A simple work-around is using the regexp_replace() function on the text representation of the JSON string to replace the relevant objects.
UPDATE my_table
SET my_data =
regexp_replace(my_data::text, '"abc"\s*:\s*\d+', '"mno":5', 'g')::jsonb
For added requirement 2:
I wrote the below query based on already given solution:
UPDATE books
SET book_info =
regexp_replace(book_info::text, '"abc"\s*:\s*true', '"xyz":1', 'g')::jsonb;
UPDATE books
SET book_info =
regexp_replace(book_info::text, '"abc"\s*:\s*false', '"xyz":0', 'g')::jsonb;
I have been searching all over to find a way to do this.
I am trying to clean up a table with a lot of duplicated jsonb fields.
There are some examples out there, but as a little twist, I need to exclude one key/value pair in the jsonb field, to get the result I need.
Example jsonb
{
"main": {
"orders": {
"order_id": "1"
"customer_id": "1",
"update_at": "11/23/2017 17:47:13"
}
}
Compared to:
{
"main": {
"orders": {
"order_id": "1"
"customer_id": "1",
"updated_at": "11/23/2017 17:49:53"
}
}
If I can exclude the "updated_at" key when comparing, the query should find it a duplicate and this, and possibly other, duplicated entries should be deleted, keeping only one, the first "original" one.
I have found this query, to try and find the duplicates. But it doesn't take my situation into account. Maybe someone can help structuring this to meet the requirements.
SELECT t1.jsonb_field
FROM customers t1
INNER JOIN (SELECT jsonb_field, COUNT(*) AS CountOf
FROM customers
GROUP BY jsonb_field
HAVING COUNT(*)>1
) t2 ON t1.jsonb_field=t2.jsonb_field
WHERE
t1.customer_id = 1
Thanks in advance :-)
If the Updated at is always at the same path, then you can remove it:
SELECT t1.jsonb_field
FROM customers t1
INNER JOIN (SELECT jsonb_field, COUNT(*) AS CountOf
FROM customers
GROUP BY jsonb_field
HAVING COUNT(*)>1
) t2 ON
t1.jsonb_field #-'{main,orders,updated_at}'
=
t2.jsonb_field #-'{main,orders,updated_at}'
WHERE
t1.customer_id = 1
See https://www.postgresql.org/docs/9.5/static/functions-json.html
additional operators
EDIT
If you dont have #- you might just cast to text, and do a regex replace
regexp_replace(t1.jsonb_field::text, '"update_at": "[^"]*?"','')::jsonb
=
regexp_replace(t2.jsonb_field::text, '"update_at": "[^"]*?"','')::jsonb
I even think, you don't need to cast it back to jsonb. But to be save.
Mind the regex matche ANY "update_at" field (by key) in the json. It should not match data, because it would not match an escaped closing quote \", nor find the colon after it.
Note the regex actually should be '"update_at": "[^"]*?",?'
But on sql fiddle that fails. (maybe depends on the postgresbuild..., check with your version, because as far as regex go, this is correct)
If the comma is not removed, the cast to json fails.
you can try '"update_at": "[^"]*?",'
no ? : that will remove the comma, but fail if update_at was the last in the list.
worst case, nest the 2
regexp_replace(
regexp_replace(t1.jsonb_field::text, '"update_at": "[^"]*?",','')
'"update_at": "[^"]*?"','')::jsonb
for postgresql 9.4
Though sqlfidle only has 9.3 and 9.6
9.3 is missing the json_object_agg. But the postgres doc says it is in 9.4. So this should work
It will only work, if all records have objects under the important keys.
main->orders
If main->orders is a json array, or scalar, then this may give an error.
Same if {"main": [1,2]} => error.
Each json_each returns a table with a row for each key in the json
json_object_agg aggregates them back to a json array.
The case statement filters the one key on each level that needs to be handled.
In the deepest nest level, it filters out the updated_at row.
On sqlfidle set query separator to '//'
If you use psql client, replace the // with ;
create or replace function foo(x json)
returns jsonb
language sql
as $$
select json_object_agg(key,
case key when 'main' then
(select json_object_agg(t2.key,
case t2.key when 'orders' then
(select json_object_agg(t3.key, t3.value)
from json_each(t2.value) as t3
WHERE t3.key <> 'updated_at'
)
else t2.value
end)
from json_each(t1.value) as t2
)
else t1.value
end)::jsonb
from json_each(x) as t1
$$ //
select foo(x)
from
(select '{ "main":{"orders":{"order_id": "1", "customer_id": "1", "updated_at": "11/23/2017 17:49:53" }}}'::json as x) as t1
x (the argument) may need to be jsonb, if that is your datatype
In Postgresql 9.6, There is a table contains a column data jsonb, it has a count field.
How to increase data->>count by 1 in a single sql? Like $inc from mongodb.
This is ugly but works. I'm just figuring this out now by readings the documentation, so there may very well be a better way of doing this.
Let's start with a simple table:
create table table1 (data jsonb);
Insert some JSON:
insert into table1 (data) values ('{"name": "example", "count": 0}');
Now, we want to update the value of the count key in the data column. Assuming that you have pg 9.5 or later, you can use the concatenation operator to merge two json (or jsonb) dictionaries, like this:
sandbox=# select data || '{"count": 1}' as data from table1;
data
---------------------------------
{"name": "example", "count": 1}
So we know how to update a JSON key. But in the above example I'm using a static value in the replacement, while we actually want "one more than the current value of count". We can use the concatenation operating with strings to build the necessary JSON:
sandbox=# select '{"count": ' || ((data->>'count')::int + 1) || '}' as count from table1;
count
--------------
{"count": 1}
Putting that together:
sandbox=# update table1 set data = data || ('{"count": ' || ((data->>'count')::int + 1) || '}')::jsonb ;
UPDATE 1
Which gets us:
sandbox=# select * from table1;
data
---------------------------------
{"name": "example", "count": 1}