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
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?
Consider the following JSON object,
[
{
"id": 5964460916832,
"name": "Size",
"value": "Small",
"position": 1,
"product_id": 4588516409440
},
{
"id": 5964460916833,
"name": "Size",
"value": "Medium",
"position": 2,
"product_id": 4588516409440
},
{
"id": 5964460916834,
"name": "Size",
"value": "Large",
"position": 3,
"product_id": 4588516409440
}
]
This is a value present in a table field called custom_attrs of JSON data type in a MySQL 8.0 table. I wanted to search the JSON data to match with multiple fields in the same object.
For example,
I wanted to see if there's a match for name "Size" and value "Medium" within the same object. It should not match the name in the first object and the value in the second object.
While we can always use JSON table, I don't prefer that due to the complexities it brings during the JOINs.
JSON_SEARCH supports LIKE operator, but it cannot ensure if it's from the same object
JSON_CONTAINS supports multiple fields but not LIKE as follows,
SET #doc = CAST('[{"id":5964460916832,"name":"Size","value":"Small","position":1,"product_id":4588516409440},{"id":5964460916833,"name":"Size","value":"Medium","position":2,"product_id":4588516409440},{"id":5964460916834,"name":"Size","value":"Large","position":3,"product_id":4588516409440}]' AS JSON);
SELECT JSON_CONTAINS(#doc, '{"name":"Size", "value":"Small"}')
Is there any way to get the same JSON_CONTAINS like functionality with partial search like, {"name":"Size", "value":"%sma%"}
Any help on this would be greatly helpful.
JSON_CONTAINS() only works with equality, not with pattern matching.
The JSON_TABLE() function is the solution intended to address the task you are trying to do. But you said you don't want to use it.
You can simulate JSON_TABLE() using other functions.
select * from (
select
json_unquote(json_extract(col, concat('$[',n.i,'].id'))) as `id`,
json_unquote(json_extract(col, concat('$[',n.i,'].name'))) as `name`,
json_unquote(json_extract(col, concat('$[',n.i,'].value'))) as `value`
from (select #doc as col) j
cross join (select 0 as i union select 1 union select 2 union select 3 union select 4 union select 5 ...) as n
) as t
where t.`id` is not null
order by id, `name`;
Output:
+---------------+------+--------+
| id | name | value |
+---------------+------+--------+
| 5964460916832 | Size | Small |
| 5964460916833 | Size | Medium |
| 5964460916834 | Size | Large |
+---------------+------+--------+
You could then easily add a condition like AND value LIKE '%sma%'.
As you can see, this query is even more complex than if you had used JSON_TABLE().
Really, any solution is going to be complex when you store your data in JSON format, then try to use SQL expressions and relational operations to query them as if they are normalized data. This is because you're practically implementing a mini-database within the functions of a real database. This is sometimes called the Inner-Platform Effect:
The inner-platform effect is the tendency of software architects to create a system so customizable as to become a replica, and often a poor replica, of the software development platform they are using. This is generally inefficient and such systems are often considered to be examples of an anti-pattern.
If you want simple queries, you should store data in normal rows and columns, not in JSON. Then you could get your result using quite ordinary SQL:
SELECT id, name, value FROM MyTable WHERE name = 'Size' AND value LIKE '%sma%';
It might be a noob question, but would like to know the capabilities of postgres json output.
For the table below:
id | seconds | datetime
1 | 10 | 2020-08-21 08:42:58.26+08
2 | 20 | 2020-08-21 10:20:00.01+08
3 | 10 | 2020-08-22 08:00:00.10+08
Is this possible to output in json like so?
[{
"date" : "2020-08-21",
"seconds_1" : 10,
"seconds_2" : 20,
},
{
"date" : "2020-08-22",
"seconds_1" : 10
}]
I can manipulate the table result thru php/javascript, but just wondering if this is possible in postgres.
This requires a multi step aggregation:
select jsonb_agg(item)
from (
select jsonb_build_object('date', dt)|| jsonb_object_agg(concat('seconds_', rn), seconds) item
from (
select datetime::date as dt,
row_number() over (partition by datetime::date) as rn,
seconds
from the_table
) t
group by dt
) r
The inner most query is used to number the rows per date, this can't be done at the same level where the grouping by date is done, because then the numbers would be wrong (as window functions are evaluated after grouping)
The second level aggregates all "seconds" for each date and builds a JSON value from that. The last level then aggregates everything into a JSON array.
Online example
If you don't care about the numbers that make the "seconds" key unique, you can use the id column and simplify the query a bit:
select jsonb_agg(item)
from (
select jsonb_build_object('date', datetime::date)|| jsonb_object_agg(concat('seconds_', id), seconds) item
from the_table
group by datetime::date
) r
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
I have a table like:
CREATE TABLE myrecord AS
id INT
other TEXT
attributes JSONB
The attributes are structured like this:
[
{"name": "a", "value": "1"},
{"name": "b", "value": "2"}
]
I'd like to convert that to a result like:
id INT, other TEXT, a TEXT, b TEXT
So that for a given row like
1 | "foo" | {..as above..}
I get a result like
1 | "foo" | "1" | "2"
Right now I'm able to unpack the attribute structure like this:
CREATE TYPE myrecord_attributes AS (name TEXT, value TEXT);
SELECT
id,
other,
(json_populate_recordset(NULL :: myrecord_attributes,
attributes :: JSON)).*
FROM myrecord
But with that I get results like:
1 | "foo" | "a" | "1"
1 | "foo" | "b" | "2"
How can I flatten the result from json_populate_recordset into the appropriate structure? I'm also open to alternate solutions which don't use it like that at all.
I'm using postgres 9.4 if that matters
You can do as this:
select m.id,
m.other,
x.value::jsonb->>'name' as name,
x.value::jsonb->>'value' as value
from myrecord m,
json_array_elements(m.attributes) x;
And if you like it to return the values with double quotes just change ->> to ->
See it working here: http://sqlfiddle.com/#!15/450cc/9
This is making use of the implicit LATERAL JOIN in Postgres 9.3 or later.
EDIT
My first solution did not meet the OP's requirements, so, I've created another solution:
select m.id,
m.other,
max(case when x.value::json->>'name' = 'a'
then x.value::json->>'value' else '' end) as a,
max(case when x.value::json->>'name' = 'b'
then x.value::json->>'value' else '' end) as b
from myrecord m,
json_array_elements(m.attributes) x
group by m.id,
m.other;
See it working here: http://sqlfiddle.com/#!15/450cc/14
Assuming that your jsonb array always has two elements as given in your question, you can explicitly select all required elements:
SELECT id, other, (attributes->0)->>'value' AS a, (attributes->1)->>'value' AS b
FROM myrecord;