I have a string object in a table column with structure:
[{"__food": "true"},{"item": "1"},{"toppings": "true"},{"__discount_amount": "4.95"},{"__original_price": "24.95"}]
How can I extract the value true from the toppings key from this?
I tried turning it into JSON first but json_extract(parse_json(string_object_column), '$.toppings') just returns null
The closest I got was keeping it as a string and doing
json_extract(string_object_column, '$[0]')
Which gets me:
{"toppings":"true"}
Is this doable without unnesting?
You may try and consider below approach using REGEXP_EXTRACT:
SELECT REGEXP_EXTRACT('[{"__food": "true"},{"item": "1"},{"toppings": "true"},{"__discount_amount": "4.95"},{"__original_price": "24.95"}]', r'"toppings": "(\D+)"}') as EXTRACT_TOPPINGS
OUTPUT:
You may just update the REGEX to make it more strict based on your use case.
Related
I have a table in athena aws where the column 'metadata_stopinfo' has the structure that you can see in the image.
I am trying to extract values that are inside that array, however when I try
SELECT
"json_extract_scalar"(metadata_stopinfo, '$.city')
FROM "table"
I have the following problem
SYNTAX_ERROR: line 2:5: Unexpected parameters (array(row("address" row("addressline" varchar,"city" varchar,"countrycode" varchar,"countrycodeoriginal" varchar,"state" varchar,"zipcode" varchar),"carrierreference" varchar,"contacts" array(row("contacttype" varchar,"email" varchar,"fax" varchar,"mobilephone" varchar,"name" varchar,"officephone" varchar,"userid" varchar)),"containerinfo" array(row("containerid" varchar,"containeridtype" varchar,"equipmentcode" varchar,"equipmenttype" varchar)),"conveyancelinenumber" varchar,"conveyancetype" varchar,"conveyancetypeoriginal" varchar,"dateinfo" row("arrivalestimateddate" varchar,"arrivalestimateddateend" varchar,"arrivalestimatedendoffset" varchar,"arrivalestimatedoffset" varchar,"arrivalrequesteddate" varchar,"deliveryestimateddate" varchar,"deliveryestimateddateend" varchar,"deliveryestimatedendoffset" varchar,"deliveryestimatedoffset" varchar,"deliveryrequesteddate" varchar,"deliveryrequesteddateend" varchar,"deliveryrequestedendoffset" varchar,"deliveryrequestedoffset" varchar,"departureestimateddate" varchar,"departureestimateddateend" varchar,"departureestimatedendoffset" varchar,"departureestimatedoffset" varchar,"departurerequesteddate" varchar,"pickuprequesteddate" varchar,"pickuprequesteddateend" varchar,"pickuprequestedendoffset" varchar,"pickuprequestedoffset" varchar,"pickupestimateddate" varchar,"pickupestimateddateend" varchar,"pickupestimatedendoffset" varchar,"pickupestimatedoffset" varchar),"deliverynotenumber" varchar,"instructions" array(row("customerspecificsubtype" varchar,"header" boolean,"instructionsubtype" varchar,"instructiontype" varchar,"text" varchar)),"locationid" varchar,"partnercarrieraddress" row("addressline" varchar,"city" varchar,"countrycode" varchar,"countrycodeoriginal" varchar,"state" varchar,"zipcode" varchar),"partnercarriercontacts" array(row("contacttype" varchar,"email" varchar,"fax" varchar,"name" varchar,"officephone" varchar)),"partnercarrierid" varchar,"partnercarriername" varchar,"partnerid" varchar,"partnername" varchar,"partnertimezone" varchar,"partnertype" varchar,"productquantity" row("number" double,"originalunitofmeasure" varchar,"quantitytype" varchar,"unitofmeasure" varchar),"sequencenumber" bigint,"shipmentidentifier" varchar,"stoptype" varchar,"transportinfo" row("description" varchar,"transportcode" varchar,"transportoriginalcode" varchar),"vesselinfo" row("lloydsnumber" varchar,"shipsradiocallnumber" varchar,"vesselname" varchar,"vesselnumber" varchar,"voyagetripnumber" varchar))), varchar(6)) for function json_extract_scalar. Expected: json_extract_scalar(varchar(x), JsonPath) , json_extract_scalar(json, JsonPath)
My question is, how can i extract values inside de column ?
json_extract_scalar unsurprisingly works with json (note that even if yur data was in json format, json_extract_scalar(metadata_stopinfo, '$.city') still would not have worked cause your data is an array), while your column contains array's of row's, so you need to work with it correspondingly. For example you can use indexes to access elements in array (in presto array indexes start from 1):
SELECT
metadata_stopinfo[1] r
FROM "table"
And then access the fields:
The fields may be of any SQL type, and are accessed with field reference operator .
SELECT
metadata_stopinfo[1].city city
FROM "table"
Also you can flatten the array with unnest:
SELECT r.city
FROM "table",
unnest(metadata_stopinfo) as t(r)
I have the following type of data as in my rows
{'new_value_formatted': 'Committed/Test Transaction', 'old_value_formatted': 'Completed'}
I would like to have new_value_formatted & old_value_formatted as individual columns and data stored in columnar manner
Tried regex '(([A-Z/ ])\w+)'. Still can't isolate.
select a.id,a.title,additional_data,
substring(b.additional_data ->> "old_value_formatted" FROM '[0-9a-zA-Z]+') as "Old Value",
substring(b.additional_data ->> "new_value_formatted" FROM '[0-9a-zA-Z]+') as "New from table a,b....
Old Value | New_Value
__________|____________
xxxxx . | xxxxx
The format presented here is not valid json. Json uses double quotes. If on postgresql 9.2+ I would do replace(data,'\'','"')::json to get valid json, taking care of quoting issues. Then you could do select new_data ->> 'new_value_formatted'
I used new_data as a placeholder for the valid json version.
If you need this for an older version, please come back to me.
P.s.: this is not tested, as I currently have no machine at hand.
I have browsed the web and forum to download the data from the file json, but my script does not work.
I have a problem with downloading the list of objects of rates. Can someone please help? I can not find fault.
{"table":"C","no":"195/C/NBP/2016","tradingDate":"2016-10-06","effectiveDate":"2016-10-07","rates":
[
{"currency":"dolar amerykański","code":"USD","bid":3.8011,"ask":3.8779},
{"currency":"dolar australijski","code":"AUD","bid":2.8768,"ask":2.935},
{"currency":"dolar kanadyjski","code":"CAD","bid":2.8759,"ask":2.9339},
{"currency":"euro","code":"EUR","bid":4.2493,"ask":4.3351},
{"currency":"forint (Węgry)","code":"HUF","bid":0.013927,"ask":0.014209},
{"currency":"frank szwajcarski","code":"CHF","bid":3.8822,"ask":3.9606},
{"currency":"funt szterling","code":"GBP","bid":4.8053,"ask":4.9023},
{"currency":"jen (Japonia)","code":"JPY","bid":0.036558,"ask":0.037296},
{"currency":"korona czeska","code":"CZK","bid":0.1573,"ask":0.1605},
{"currency":"korona duńska","code":"DKK","bid":0.571,"ask":0.5826},
{"currency":"korona norweska","code":"NOK","bid":0.473,"ask":0.4826},
{"currency":"korona szwedzka","code":"SEK","bid":0.4408,"ask":0.4498},
{"currency":"SDR (MFW)","code":"XDR","bid":5.3142,"ask":5.4216}
],
"EventProcessedUtcTime":"2016-10-09T10:48:41.6338718Z","PartitionId":1,"EventEnqueuedUtcTime":"2016-10-09T10:48:42.6170000Z"}
This is my script in sql.
#trial =
EXTRACT jsonString string
FROM #"adl://kamilsepin.azuredatalakestore.net/ExchangeRates/2016/10/09/10_0_c60d8b8895b047c896ce67d19df3cdb2.json"
USING Extractors.Text(delimiter:'\b', quoting:false);
#json =
SELECT Microsoft.Analytics.Samples.Formats.Json.JsonFunctions.JsonTuple(jsonString) AS rec
FROM #trial;
#columnized =
SELECT
rec["table"]AS table,
rec["no"]AS no,
rec["tradingDate"]AS tradingDate,
rec["effectiveDate"]AS effectiveDate,
rec["rates"]AS rates
FROM #json;
#rateslist =
SELECT
table, no, tradingDate, effectiveDate,
Microsoft.Analytics.Samples.Formats.Json.JsonFunctions.JsonTuple(rates) AS recl
FROM #columnized;
#selectrates =
SELECT
recl["currency"]AS currency,
recl["code"]AS code,
recl["bid"]AS bid,
recl["ask"]AS ask
FROM #rateslist;
OUTPUT #selectrates
TO "adl://kamilsepin.azuredatalakestore.net/datastreamanalitics/ExchangeRates.tsv"
USING Outputters.Tsv();
You need to look at the structure of your JSON and identify, what constitutes your first path inside your JSON that you want to map to correlated rows. In your case, you are really only interested in the array in rates where you want one row per array item.
Thus, you use the JSONExtractor with a JSONPath that gives you one row per array element (e.g., rates[*]) and then project each of its fields.
Here is the code (with slightly changed paths):
REFERENCE ASSEMBLY JSONBlog.[Newtonsoft.Json];
REFERENCE ASSEMBLY JSONBlog.[Microsoft.Analytics.Samples.Formats];
#selectrates =
EXTRACT currency string, code string, bid decimal, ask decimal
FROM #"/Temp/rates.json"
USING new Microsoft.Analytics.Samples.Formats.Json.JsonExtractor("rates[*]");
OUTPUT #selectrates
TO "/Temp/ExchangeRates.tsv"
USING Outputters.Tsv();
I have a database with a json field which has multiple parts including one called tags, there are other entries as below but I want to return only the fields with "{"tags":{"+good":true}}".
"{"tags":{"+good":true}}"
"{"has_temps":false,"tags":{"+good":true}}"
"{"tags":{"+good":true}}"
"{"has_temps":false,"too_long":true,"too_long_as_of":"2016-02-12T12:28:28.238+00:00","tags":{"+good":true}}"
I can get part of the way there with this statement in my where clause trips.metadata->'tags'->>'+good' = 'true' but that returns all instances where tags are good and true including all entries above. I want to return entries with the specific statement "{"tags":{"+good":true}}" only. So taking out the two entries that begin has_temps.
Any thoughts on how to do this?
With jsonb column the solution is obvious:
with trips(metadata) as (
values
('{"tags":{"+good":true}}'::jsonb),
('{"has_temps":false,"tags":{"+good":true}}'),
('{"tags":{"+good":true}}'),
('{"has_temps":false,"too_long":true,"too_long_as_of":"2016-02-12T12:28:28.238+00:00","tags":{"+good":true}}')
)
select *
from trips
where metadata = '{"tags":{"+good":true}}';
metadata
-------------------------
{"tags":{"+good":true}}
{"tags":{"+good":true}}
(2 rows)
If the column's type is json then you should cast it to jsonb:
...
where metadata::jsonb = '{"tags":{"+good":true}}';
If I get you right, you can check text value of the "tags" key, like here:
select true
where '{"has_temps":false,"too_long":true,"too_long_as_of":"2016-02-12T12:28:28.238+00:00","tags":{"+good":true}}'::json->>'tags'
= '{"+good":true}'
suppose we have a model in django defined as follows:
class Literal:
name = models.CharField(...)
...
Name field is not unique, and thus can have duplicate values. I need to accomplish the following task:
Select all rows from the model that have at least one duplicate value of the name field.
I know how to do it using plain SQL (may be not the best solution):
select * from literal where name IN (
select name from literal group by name having count((name)) > 1
);
So, is it possible to select this using django ORM? Or better SQL solution?
Try:
from django.db.models import Count
Literal.objects.values('name')
.annotate(Count('id'))
.order_by()
.filter(id__count__gt=1)
This is as close as you can get with Django. The problem is that this will return a ValuesQuerySet with only name and count. However, you can then use this to construct a regular QuerySet by feeding it back into another query:
dupes = Literal.objects.values('name')
.annotate(Count('id'))
.order_by()
.filter(id__count__gt=1)
Literal.objects.filter(name__in=[item['name'] for item in dupes])
This was rejected as an edit. So here it is as a better answer
dups = (
Literal.objects.values('name')
.annotate(count=Count('id'))
.values('name')
.order_by()
.filter(count__gt=1)
)
This will return a ValuesQuerySet with all of the duplicate names. However, you can then use this to construct a regular QuerySet by feeding it back into another query. The django ORM is smart enough to combine these into a single query:
Literal.objects.filter(name__in=dups)
The extra call to .values('name') after the annotate call looks a little strange. Without this, the subquery fails. The extra values tricks the ORM into only selecting the name column for the subquery.
try using aggregation
Literal.objects.values('name').annotate(name_count=Count('name')).exclude(name_count=1)
In case you use PostgreSQL, you can do something like this:
from django.contrib.postgres.aggregates import ArrayAgg
from django.db.models import Func, Value
duplicate_ids = (Literal.objects.values('name')
.annotate(ids=ArrayAgg('id'))
.annotate(c=Func('ids', Value(1), function='array_length'))
.filter(c__gt=1)
.annotate(ids=Func('ids', function='unnest'))
.values_list('ids', flat=True))
It results in this rather simple SQL query:
SELECT unnest(ARRAY_AGG("app_literal"."id")) AS "ids"
FROM "app_literal"
GROUP BY "app_literal"."name"
HAVING array_length(ARRAY_AGG("app_literal"."id"), 1) > 1
Ok, so for some reason none of the above worked for, it always returned <MultilingualQuerySet []>. I use the following, much easier to understand but not so elegant solution:
dupes = []
uniques = []
dupes_query = MyModel.objects.values_list('field', flat=True)
for dupe in set(dupes_query):
if not dupe in uniques:
uniques.append(dupe)
else:
dupes.append(dupe)
print(set(dupes))
If you want to result only names list but not objects, you can use the following query
repeated_names = Literal.objects.values('name').annotate(Count('id')).order_by().filter(id__count__gt=1).values_list('name', flat='true')