I have column response_payload in table response as below
{"studentName":"Karate","studentStream":"API Testing", "studentAge":18}
Now I need to get the new json object based on my keys. For example, if my keys are studentName and studentStream I must get
{"studentName":"Karate","studentStream":"API Testing"}
In case if I provide invalid key, it should not bring anything related to invalid key.
I have tried json_build_object built-in function in postgresql, it is bringing invalid key and value as below
select json_build_object('invalidKey', payload -> 'invalidValue')
from response
O/P:- {"invalidKey":"null"}
I want output when invalid key and value is provided, it should not bring anything as below
O/p:- {}
You can use jsonb_strip_nulls
select
jsonb_strip_nulls(jsonb_build_object('invalidKey', payload -> 'invalidValue'))
from response
Related
I have data in the comment column of the payments table. The data is stored as plain text in the following format:
{"foo"=>"bar"}
I need to query the value of the specific "foo" key and tried the following:
select comment::json -> 'foo' from payments
but because the data stored is not in JSON format I get the following error:
invalid input syntax for type json DETAIL: Token "=" is invalid. CONTEXT: JSON data, line 1: {"foo"=>"bar"}
which refers to the => that Ruby uses for Hashes.
Is there a way to convert the text data to JSON data on-the-fly so I can then access the specific keys I need?
You can replace the => with a : to make that example a valid JSON value:
replace(comment, '=>', ':')::jsonb ->> 'foo'
It sounds like the data is technically valid ruby which means we can do something a bit clever.
require 'json'
def parse_data(data_string)
eval(data_string).to_json
end
Should do the trick so long as the data is trusted.
I log messages that are JSON objects. The JSON has an array that contains key/value pairs:
{
...
"arr": [{"key": "foo", "value": "bar"}, ...],
...
}
Now I want to filter results that contains a specific key and extract the values for a specific key in the array.
I've tried using regex, something like parse #message /.*"key":"my_specific_key","value":(?<value>.*}).*/ which extracts the value but also returns the rest of the message. Also it doesn't filter the results.
How can I filter results and extract the values for a specific key?
If in your log entry in the cloudwatch log group they are actually showing up as json, you can just reference the key directly in any place you would a field.
(don't need the #, cloudwatch appends that automatically to all default values)
If you are using python, you can use aws_lambda_powertools to do this as well, in a very slick way (and its an actual aws product)
If they are showing up in your log as a string, then it may be an escaped string and you'll have to match it -exactly- - including spaces and what not. when you parse, you will want to do something like this:
if this is the string of your log message '{"AKey" : "AValue", "Key2" : "Value2"}
parse #message "{\"*\" : \"*\",\"*\" : \"*\"} akey, akey_value, key2, key2_value
then you can filter or count or anything against those variables. parse is specifically a statement to match a pattern and assign the wildcard to a variable, one at a time in order
tho with a complex json, if your above regex works than all you need is a filter statement
field #message
| pares #message ... your regex as value_var
| filer value_var /some more regex/
if its not a string in the log entry, but an actual json, you can just reference against the key:
filter a_key ~="some value" (or regex here)
https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/CWL_AnalyzeLogData-discoverable-fields.html
for more info
I have got like this meta key a:1:{s:8:"investor";b:1;} but i want get only one string like "investor" in switch case condition.
My current table in BigQuery has a column that uses complex types. The "family" column is actually a list ("repeated" feature) of records (with 2 fields: id & name).
When I try to get the 1st "id" value of 1 row with the following syntax:
FieldValueList c = qr.getValues().iterator().next();
c.get("family").getRepeatedValue().get(0).getRecordValue().get("id");
I get the exception:
Method threw 'java.lang.UnsupportedOperationException' exception.
Retrieving field value by name is not supported when there is no fields schema provided
This is a bit annoying because my table has a clearly defined schema. And when I do the "read" query with the same Java call, I can also see that this schema is correctly found:
qr.getSchema().getFields().get("family").getSubFields().toString();
-->
[Field{name=id, type=INTEGER, mode=NULLABLE, description=null}, Field{name=name, type=STRING, mode=NULLABLE, description=null}]
Due to this exception, the workaround that I have found is to pass the "index" of the record field instead of giving it its name
c.get("family").getRepeatedValue().get(0).getRecordValue().get(0).getLongValue();
However, this seeks awkward to pass an index instead of a name.
Is there a better way to get the value of a field in a record inside an array (if my column is only a record, without array, then I don't get the exception) ?
Is this exception normal?
You can wrap the unnamed FieldValueList with a named one using the "of" static method:
FieldList subSchema = qr.getSchema().getFields().get("family").getSubFields();
FieldValueList c = qr.getValues().iterator().next();
FieldValueList.of(
c.get("family").getRepeatedValue().get(0).getRecordValue(),
subSchema).get("id");
The "of" method takes a FieldValueList (returned by getRecordValue() in this case) and a FieldList (subSchema here), and returns the same FieldValueList but with named access.
I have checked following, but didn't work.
https://redis.io/commands/keys
KEYS Room:*
1) "Room:120"
2) "Room:121"
3) "Room:122"
Following is the redis key/values (HMSET)
Room:120 [SocketId:mOQDJusPjDTBN5L-AAAC,TimeStamp:10-10-2017 12:10:00 AM]
Room:121 ....
Room:122 ....
...
Need to search as Room:* SocketId:mOQDJusPjDTBN5L-AAAC
How can I search for SocketId in the collection ?
Need to search with:
mOQDJusPjDTBN5L-AAAC
The question is not so clear
as u mentioned hmset i am assuming that you are using hashes to store your data.
As per your data,
'room120' should be the key, 'socketId' should be the field and 'mOQDJusPjDTBN5L-AAAC' should be the value.
so in order to search for socketId you can use hscan,where hscan iterates through the field of a particular key.https://redis.io/commands/scan
in case if you are just using key/value storage i.e
'socketId' being the key ,'mOQDJusPjDTBN5L-AAAC' being the value.
here u can just use the command Keys *socket*to search for the key socketId