Suppose I have following json and I want to skip the entry "data_type" from it.
{
"marketing_type":"FIT",
"controllable":"true",
"plannable":"true",
"sbm_qualified":"true",
"marginal_cost":"{:type=>\"float\", :label=>\"Marginal Cost to steer\",:unit=>\"$/MWh\", :default=>100} must be float.",
"data_type": "any_value",
"start_cost":"{:type=>\"float\", :label=>\"Start Cost\", :unit=>\"$\",:default=>0} must be float."
}
Expected output is "data_type" entry should be removed from above.
Instead of using regex and string manipulations, and if you're running at least MySQL 5.7, you can use one of the built-in JSON functions, json_remove:
update table_name set column_name = json_remove(column_name, "$.data_type")
Related
I have a column named data and I have to update its content from something like {} to [{}] for each record in table A, I tried to use JSON_ARRAY() but it gives me a quoted
["{\"something\": \"true\"}"]
but I'd like to have something like
[{ "something": "true" }]
How I do it now?
SELECT JSON_ARRAY(data) FROM A;
How should I update it either using JSON_SET() or UPDATE?
You need to use a path to get the data as JSON, rather than referring to the column by itself. The path $ means the top-level object.
update A
SET data = CASE
WHEN data IS NULL THEN '[]' -- NULL becomes empty array
WHEN LEFT(data, 1) = '[' THEN data -- leave existing array alone
ELSE JSON_ARRAY(data->"$") -- put object inside array
END
DEMO
Try using
SELECT JSON_ARRAY_AGG(JSON_OBJECT(data)) from A;
I have a big JSON data in one column called response_return in a Postgres DB, with a response like:
{
"customer_payment":{
"OrderId":"123456789",
"Customer":{
"Full_name":"Francis"
},
"Payment":{
"AuthorizationCode":"9874565",
"Recurrent":false,
"Authenticate":false,
...
}
}
}
I tried to use Postgres functions like -> ,->> ,#> or #> to walk through headers to achieve AuthorizationCode for a query.
When I use -> in customer_payment in a SELECT, returns all after them. If I try with OrderId, it's returned NULL.
The alternatives and sources:
Using The JSON Datatype In PostgreSQL
Operator ->
Allows you to select an element based on its name.
Allows you to select an element within an array based on its index.
Can be used sequentially: ::json->'elementL'->'subelementM'->…->'subsubsubelementN'.
Return type is json and the result cannot be used with functions and operators that require a string-based datatype. But the result can be used with operators and functions that require a json datatype.
Query for element of array in JSON column
This is not helpful because I don't want filter and do not believe that need to transform to array.
If you just want to get a single attribute, you can use:
select response_return -> 'customer_payment' -> 'Payment' ->> 'AuthorizationCode'
from the_table;
You need to use -> for the intermediate access to the keys (to keep the JSON type) and ->> for the last key to return the value as a string.
Alternatively you can provide the path to the element as an array and use #>>
select response_return #>> array['customer_payment', 'Payment', 'AuthorizationCode']
from the_table;
Online example
I want to check if an array of strings occur in a dataset and print those rows where the string array elements occur.
rareTitles = {"Capt", "Col", "Countess", "Don", "Dr", "Jonkheer", "Lady",
"Major", "Mlle", "Mme", "Ms", "Rev", "Sir"}
dataset[rareTitles in (dataset['Title'])]
I am getting following error:
TypeError: unhashable type: 'set'
First of all, I think the comparison should go the other way around - you look for a dataset['Title'], that contains string from rareTitles.
You can use str attribute of a pandas DataSeries, which allows as to use string methods, like contains. As this method accepts also a pattern as a regular expression, you can put as an argument something like 'Capt|Col...'. To join all elements of a set you can use str.join() method.
So the solution would be
dataset[dataset['Title'].str.contains('|'.join(rareTitles))]
Link to documentation: pandas.Series.str.contains
I have a column named params in a table named reports which contains JSON.
I need to find which rows contain the text 'authVar' anywhere in the JSON array. I don't know the path or level in which the text could appear.
I want to just search through the JSON with a standard like operator.
Something like:
SELECT * FROM reports
WHERE params LIKE '%authVar%'
I have searched and googled and read the Postgres docs. I don't understand the JSON data type very well, and figure I am missing something easy.
The JSON looks something like this.
[
{
"tileId":18811,
"Params":{
"data":[
{
"name":"Week Ending",
"color":"#27B5E1",
"report":"report1",
"locations":{
"c1":0,
"c2":0,
"r1":"authVar",
"r2":66
}
}
]
}
}
]
In Postgres 11 or earlier it is possible to recursively walk through an unknown json structure, but it would be rather complex and costly. I would propose the brute force method which should work well:
select *
from reports
where params::text like '%authVar%';
-- or
-- where params::text like '%"authVar"%';
-- if you are looking for the exact value
The query is very fast but may return unexpected extra rows in cases when the searched string is a part of one of the keys.
In Postgres 12+ the recursive searching in JSONB is pretty comfortable with the new feature of jsonpath.
Find a string value containing authVar:
select *
from reports
where jsonb_path_exists(params, '$.** ? (#.type() == "string" && # like_regex "authVar")')
The jsonpath:
$.** find any value at any level (recursive processing)
? where
#.type() == "string" value is string
&& and
# like_regex "authVar" value contains 'authVar'
Or find the exact value:
select *
from reports
where jsonb_path_exists(params, '$.** ? (# == "authVar")')
Read in the documentation:
The SQL/JSON Path Language
jsonpath Type
{
"Actor": {
"knownlanguages": [
"English"
]
}
}
This JSON is stored in JSON columntype of MySQL with name data.
My question is how to check whether knownlanguages key contains value English from JSON datatype of MySQL using query?
Easy:
SELECT * FROM table WHERE JSON_CONTAINS(json, '"English"', "$.Actor.knownlanguages")
or (depending on what you have to do):
SELECT JSON_CONTAINS(json, '"English"', "$.Actor.knownlanguages") FROM table
reference: https://dev.mysql.com/doc/refman/5.7/en/json-search-functions.html
you can use like keyword with wildcard %
SELECT * FROM table where data like "%English%"
NOTE:
this won't search in JSON field knownlanguages, but in column data