So, my problem is, that in MongoDB that .aggregate() function is not working
Heres some pictures:
You can see what a tried on the first picture
When using "$lookup", it's important that both "localField" values and "foreignField" values have the same type.
In this case, "localField" is a string and "foreignField" is an ObjectId.
It's probably best for queries to use ObjectId's for both.
Related
I am trying to pass an array as query parameter in Postman.
I am calling DELETE method to delete a user from list of databases. It is expecting list of database names as array in the query parameter. When I pass as given below, I am getting error.
{"code":2,"message":"data_services must be an array and not empty"}
Please let me know, how can I pass an array as query parameter in Postman.
You need to create 2 keys with the same name and add postfix []
You can specify the parameter key multiple times with different values.
Don't use square brackets or numbers like an array in code.
This will result in a query string like so:
?data_services=somename&data_services=anothername
I mis-read the DELETE method. It was expecting array of databases in the body of the Http body section, instead of on query parameter section. I provided the array as given below and it got succeeded.
The below is the way, I passed array to Http request in the body section.
can you check below link it is useful for you
https://medium.com/#darilldrems/how-to-send-arrays-with-get-or-post-request-in-postman-f87ca70b154e
I am using PostgreSQL 9.5.14, and have a column in a table that contains JSON arrays that I need to parse for their contents.
Using a select I can see that the structure of the JSON is of this kind:
SELECT rule_results from table limit 5;
Result:
[{"rule_key":"applicant_not_lived_outside_eu"},{"rule_key":"family_assets_exceed_limit"},{"rule_key":"owned_a_deed"}]
[]
[]
[{"rule_key":"family_category","details":"apply_with_parents_under_25"}]
[]
I have been unable to create an SQL command to give me the values of the rule_key keys.
I've attempted to use the documentation for json-functions in postgresql to find a solution from
https://www.postgresql.org/docs/9.5/functions-json.html
SELECT rule_results::json->'rule_key' as results from table;
This gives me null values only.
SELECT jsonb_object_keys(rule_results::jsonb) from table;
This results in the error msg "cannot call jsonb_object_keys on a scalar", which seems to mean that the query is limited to a single row.
This looks simple enough, an array with key:value pairs, but somehow the answer eludes me. I would appreciate any help.
demo: db<>fiddle
Different solutions are possible. It depends on what you are expecting finally. But all solutions would use the function json_array_elements(). This expands every element into one row. With that you can do whatever you want.
This results in one row per value:
SELECT
value -> 'rule_key'
FROM
data,
json_array_elements(rule_results)
I am trying to convert Swift [Object]() array to Realm's Results<Object>!. I know that vice-versa is possible (you can see here) but is it possible to do what I want?
So I want something like result as! [Object].
Result objects are proxies for data stored in the db. You can only get them via queries, but cannot instantiate them yourself (see the docs).
To still get Result objects, you'd have to run a new query for the objects you already have, and use the returned Result... I would not suggest that though.
I´m using flink to load a csv file to a dataset of pojos, defined through a scala case class, using readCsvFile method, and I have a problem that i cannot solve.
When in the csv there is a record with some format error in any of its fields it is discarded, and I assume that the only way to keep those records is to type them all as String and do the validations myself.
The problem is that if the last field after the delimiter is empty, the record is discarded by default, I think because it is considered as not having the expected number of fields it should, and it is not possible to handle this record error, while if the empty value if in any of the previous fields there is no problem.
Example
field1|field2|field3
a||c
a|b|
In this example, first record is returned by readCsvFile method but not the second.
Is this behaviour right? and there is any walk around to get the record?
Thanks
Case classes and tuples in Flink do not support null values. Therefore, a||c is invalid if the empty field is not a String. I recommend to use the RowCsvInputFormat in this case. It supports nulls and generic rows can be converted to any other class in a following map operator.
The problem is that, as you say, if the field is a String, the record should be valid even if it is null, and this doesn't happen when the null value is in the last field. The behaviour is different depending on the position.
I will try also with RowCsvInputFormat as you recommend.
Thanks
Is it possible to do an array formula with index match:
e.g:
=arrayformula(if(len(A3:A),INDEX('SheetB'!E:E,MATCH(A3:A,'SheetB'!H:H,0))))
If not, is there a solution that doesn't involve google scripts?
It seems INDEX can not return multiple values. It can not be used inside ARRAYFORMULA.
The only solution I know of is to use VLOOKUP.
See this thread :
https://productforums.google.com/forum/#!topic/docs/jVvjbz8u7A8
Example from there :
=ArrayFormula(VLOOKUP( B12:B15; H2:R32; 1; TRUE))
Cheers!
Use XLOOKUP
=ARRAYFORMULA(XLOOKUP(K2:K,R2:R,S2:S))
With XLOOKUP you can look in one column for a search term, and return a result from the same row in another column, regardless of which side the return column is on
In the OP's specific case, one can actually use VLOOKUP for its intended purpose, as a replacement for MATCH:
=arrayformula(if(len(A3:A),VLOOKUP(A3:A,{SheetB!E:E,SheetB!H:H},2,false)))
In the general case of trying to use INDEX to retrieve multiple values, it can be replaced with a kludge of VLOOKUP and SEQUENCE:
=arrayformula(VLOOKUP(A:A,{SEQUENCE(rows(B:B)),B:B},2,true))
does what would have been accomplished by
=arrayformula(INDEX(B:B,A:A))
if the latter worked as OP expected.
I know this is old now, but it turns out that INDEX() acts as a defacto ARRAYFORMULA() now. You can see a fabulous example of this on this google sheet, which shows how to use a and index(split()) to extract a particular set of text from a cell. The MK.demo tab provides a visual on how the array formula is implied with the INDEX() function.
Nowadays, using a FILTER() or QUERY() function can give the kinds of multiple vlookup the OP was looking for.
im not sure if its gonna work but i did an "IF(ISBLANK() before the INDEX(...) in the ARRAYFORMULA and it went down all the way