I'm trying to map two columns into one on Athena using JsonSerDe properties.
In this case, I want to map both columns conversionsRate and cr from jsons 1 and 2 to column cr_new (doing like a coalesce).
json1
{
"deviceType": "TABLET",
"day": "2018-10-27",
"conversionsRate": 0,
"clicksCount": 3
}
json2
{
"deviceType": "TABLET",
"day": "2018-10-29",
"cr": 2,
"clicksCount": 5
}
The expected result on Athena:
|deviceType|day |cr_new|clicksCount|
|TABLET |2018-10-27|0 |3 |
|TABLET |2018-10-29|2 |5 |
Is it possible to achieve such a result on athena table mapping using SerDe?
JSON SerDe does not mandate (restrict) that column defined in the table DDL should exist in the JSON record. If there is no such attribute, JSONSerDe will return NULL. So, you can define both columns and apply coalesce in the query:
CREATE EXTERNAL TABLE json_table (
devicetype string,
`day` date,
cr int,
conversionsrate int,
clickscount int
)
ROW FORMAT SERDE 'org.openx.data.jsonserde.JsonSerDe'
LOCATION 's3://bucket/path/'; --JSON files location
--make sure JSONs are in separate lines each
select deviceType, `day`, coalesce(conversionsRate ,cr) as cr_new, clicksCount
from json_table ;
Related
I want to build a json object where only non-null values are included. For example:
SELECT
id,
jsonb_build_object(
'price', price,
'item_returned_date', item_returned_date
) as data
from table
would return the following if the first row had null item_returned date:
id | data
1 {"price": 50}
2 {"price": 100, "item_returned_date: "2022-10-01"}
Is this possible without writing a complex function?
Need help with json deserialization in postgresql. I would like this query
select data from panel
that returns:
Data
1 [{"type": "opened","user": "1"},{"type": "added","user":"2"}]
2 [{"type": "added","user": "3"}]
3 [{"type": "opened","user": "3"},{"type": "opened","user":"2"}]
instead returned a table:
type user
opened 1
added 2
added 3
opened 3
opened 2
I don't quite understand how to represent the empty space between [ and {. I would appreciate any guidance as I have not found this particular example
Use jsonb_array_elements to turn the arrays in to rows, then extract the keys:
select a.item ->> 'type' as type,
a.item ->> 'user' as "user"
from panel
cross join jsonb_array_elements(data) as a(item);
This assumes that data is defined with the data type jsonb (which it should be). If it's not, you have to cast it: data::jsonb
I have a table where each row has a json column named data_object. I want to get the data_object for each row and create a json array that represents all rows in the table.
Example:
id | data_object
----------------
1 | { "someKey": "someValue", etc. }
2 | { "someKey": "someOtherValue", etc. }
Desired Result:
[
{ "someKey": "someValue", etc. },
{ "someKey": "someOtherValue", etc. }
]
Some of the keys per row are known (a standard set), but some of the the keys per row will vary, I just want a json array that represents all rows in the table for the data_object json column.
I appreciate your help in advance!
You can use
select array_agg(data_object) from table_name;
jsonb_agg is what you're looking for:
SELECT jsonb_agg(data_object) FROM mytable
Demo: db<>fiddle
I am inserting my data in a database with json_encoded. Now I want to search in "feature", but the result is not exactly true.
MySQL query:
select *
from `modul_69`
where `extmod` like '%"68":%'
and `extmod` like '%"4"%'
and `extmod` not like '%"4":%'
Results:
row1 data:
{"68":["1","4","7"],"67":["14"],"75":["28"]} - true
row2 data:
{"68":["59"],"67":["1","11","13"],"75":["3","4","5","27"]} - false
I want select only row1 by key:68 and value:4
Please help
Here is one way to do it using MySQL JSON functions, available since version 5.7:
select *
from t
where json_search(js -> '$."68"', 'one', '4') is not null
What this does is get the array that correspond to outer key '68' (using ->, which is a syntactic sugar for json_extract()), and then search its content with json_search(); if a non-null value is returned, we have a match.
To find if the value '"4"' is contained in the member '"68"', you can first extract the array using JSON_EXTRACT() :
SELECT JSON_EXTRACT(m.extmod, '$."68"')
FROM modul_69 m;
This outputs
["1", "4", "7"]
["59"]
To search in a JSON array if it contains a specific value, you can use JSON_CONTAINS() :
SELECT JSON_CONTAINS('["1", "4", "7"]', '"4"', '$'); -- output is 1
SELECT JSON_CONTAINS('["59"]', '"4"', '$'); -- output is 0
Now you can combine both functions to get the rows that contains the expected value :
Schema (MySQL v5.7)
CREATE TABLE modul_69
(
extmod JSON
);
INSERT INTO modul_69 VALUES ('{"68":["1","4","7"],"67":["14"],"75":["28"]}'), ('{"68":["59"],"67":["1","11","13"],"75":["3","4","5","27"]}');
Query #1
SELECT *
FROM modul_69 m
WHERE JSON_CONTAINS(JSON_EXTRACT(m.extmod, '$."68"'),
'"4"',
'$') = 1;
Output
| extmod |
| --------------------------------------------------- |
| {"67": ["14"], "68": ["1", "4", "7"], "75": ["28"]} |
View on DB Fiddle
I have scenario where i need to search multiple values in a JSON array. Below is my schema.
ID DATA
1 {"bookIds" : [1,2,3,5], "storeIds": [2,3]}
2 {"bookIds" : [1,2], "storeIds": [1,3]}
3 {"bookIds" : [11,12,10,9], "storeIds": [4,3]}
I want all the rows with value 1,2. Below is query i am using (This is query is written by one of fellow stackoverflow user Mr. klin credit to him).
select t.*
from JSONTest t, json_array_elements(data->'bookIds') books
where books::text::int in (1, 2);
However output I am duplicate rows in output, below is my output.
id data
1 {"bookIds" : [1,2,3,5], "storeIds": [2,3]}
1 {"bookIds" : [1,2,3,5], "storeIds": [2,3]}
2 {"bookIds" : [1,2], "storeIds": [1,3]}
2 {"bookIds" : [1,2], "storeIds": [1,3]}
I want only two rows in output that is id 1,2. How can i do that? I don't want use Distinct due to other constraints,
SQL Fiddle : http://sqlfiddle.com/#!15/6457a/2
Unfortunately there is no direct conversion function from a JSON array to a "real" Postgres array. (data ->'bookIds')::text returns something that is nearly a Postgres array literal: e.g. [1,2,3,5]. If you replace the [] with {} the value can be cast to an integer array. Once we have a proper integer array we can use the #> to test if it contains another array:
select *
from jsontest
where translate((data ->'bookIds')::text, '[]', '{}')::int[] #> array[1,2];
translate((data ->'bookIds')::text, '[]', '{}') will convert [1,2,3,5] to {1,2,3,5} which then is converted to an array using ::int[]
SQLFiddle: http://sqlfiddle.com/#!15/6457a/4