Forum Discussion
JSON Joining Records in Groups
Hi Community,
I am trying to retrieve records from an API that returns a Json formatted output in max groups of 1,000 records per request.
I have 10,000 journal records to get so i query the API to get each group of 1,000 records via incrementing the SKIP step.
Query1
let
Source = Json.Document(Web.Contents("http://localhost:8080/AccountRight/FileID/GeneralLedger/JournalTransaction/?$top=1000"))
in
Source
Query2
let
Source = Json.Document(Web.Contents("http://localhost:8080/AccountRight/FileID/GeneralLedger/JournalTransaction/?$top=1000&$skip=1000"))
in
Source
So i ended up with 9 queries for each group of 1000 records and then a Table.Combine to consolidated tables into one master listing....it was probably an inefficent way to do this.
I was reading Chris Webb and ImkeF posts about solving types of issues with API pagination limits and using functions to automate the get data part but i need some help with getting the list of journals to combine.
I wasnt sure best way to complete next step.
I am given then number count of records and nextpageLink for the URI for next 1000 journals.
I can generate a query to return the number of records
let
Source = Json.Document(Web.Contents("http://localhost:8080/AccountRight/FileId/GeneralLedger/JournalTransaction/")),
Items = Source[Count]
in
Items
This returns a value of 9766 shown in the source datawindow above. So if i divide this by 1000 i get the number of page calls i need to make to get all journal transactions.
I can now create a function to grab records by entering a SkipValue, so that seems to work okay...
(SkipValue as text) =>
let
Source = Json.Document(Web.Contents("http://localhost:8080/AccountRight/FileId/GeneralLedger/JournalTransaction/?$stop=1000&$skip=" & SkipValue "))
in
Source
How do i integrate the function with data so i can combine this into 1 table dynamically ?
How do i get the Skip values required for each source page of data lists?
Can anyone point me in right direction?
Thanks again for any assistance...and Merry Xmas everyone
Hi THEG72,
After research, there is a blog discribed how to implement REST API pagination in Power Query, and similar thread for your reference.
How To Do Pagination In Power Query
Creating a loop for fetching paginated data from a REST APIBest Regards,
AngeliaHi Garry, thanks for the pics. If your list contains all the data already, there is no need to use the other technique I've suggested. Just do the following:
1) Delete the steps after "Pages"
2) Transform your list to a table:
3) Expand the column by clicking on the arrows (1) and deselect the other fields (2) like this:
Thanks for this....it combined as you have advised and i have expanded the records containing the data to reveal all the 9.766 records....You are a STAR :)...I got lost a bit on this as you are right this structured Json file is odd....Expanded data 8 times to reveal entries
I had to expand the data many times to extract the final information
Here is the final code
let
BaseUrl = "http://localhost:8080/AccountRight/FileID/GeneralLedger/",
EntitiesPerPage = 1000,GetJson = (Url) =>
let Rawdata = Web.Contents(Url),
Json = Json.Document(RawData)
in Json,GetTotalEntities = () =>
let Json = Json.Document(Web.Contents("http://localhost:8080/AccountRight/fileID/GeneralLedger/")),
Items = Json[Count]
in
Items,GetPage = (Index) =>
let skip = "$skip=" & Text.From(Index * EntitiesPerPage),
Url = BaseUrl & "&" & skip
in Url,EntityCount = List.Max({EntitiesPerPage, GetTotalEntities()}),
PageCount = Number.RoundUp(EntityCount / EntitiesPerPage),
PageIndices = {0 .. PageCount - 1},URLs = List.Transform(PageIndices, each GetPage(_)),
Pages = List.Transform(URLs, each GetJson(_)),#"Converted to Table" = Table.FromList(Pages, Splitter.SplitByNothing(), null, null, ExtraValues.Error),
#"Expanded {0}" = Table.ExpandRecordColumn(#"Converted to Table", "Column1", {"Items"}, {"Column1.Items"}),
#"Expanded {0}1" = Table.ExpandListColumn(#"Expanded {0}", "Column1.Items"),
#"Expanded {0}2" = Table.ExpandRecordColumn(#"Expanded {0}1", "Column1.Items", {"UID", "DisplayID", "JournalType", "SourceTransaction", "DateOccurred", "DatePosted", "Description", "Lines", "URI", "RowVersion"}, {"UID", "DisplayID", "JournalType", "SourceTransaction", "DateOccurred", "DatePosted", "Description", "Lines", "URI", "RowVersion"}),
#"Expanded {0}3" = Table.ExpandRecordColumn(#"Expanded {0}2", "SourceTransaction", {"UID", "TransactionType", "URI"}, {"UID.1", "TransactionType", "URI.1"}),
#"Expanded {0}4" = Table.ExpandListColumn(#"Expanded {0}3", "Lines"),
#"Expanded {0}5" = Table.ExpandRecordColumn(#"Expanded {0}4", "Lines", {"Account", "Amount", "IsCredit", "Job", "LineDescription", "ReconciledDate"}, {"Account", "Amount", "IsCredit", "Job", "LineDescription", "ReconciledDate"}),
#"Expanded {0}6" = Table.ExpandRecordColumn(#"Expanded {0}5", "Job", {"UID", "Number", "Name", "URI"}, {"UID.2", "Number", "Name", "URI.2"}),
#"Expanded {0}7" = Table.ExpandRecordColumn(#"Expanded {0}6", "Account", {"UID", "Name", "DisplayID", "URI"}, {"UID.3", "Name.1", "DisplayID.1", "URI.3"})in
#"Expanded {0}7"I did a count of the UID's and it returned 9,766 dated from 2014 till November 2017 and the file size is about 2.7meg.
ImkeF just another question if I can. would you recommend this method to capture the accounting transactions for historical periods or summarise this data? I know the loading of historical data can increase load time....If it can be summarised is this a better approach as more transactions are added?
Again, thanks for your expertise on the matter.....and Happy New Year everyone!
Hi Garry,
I had a different understanding of your actual data.
I believe you just need to test out different versions and see for yourself which one is faster at the end.
Imke Feldmann
www.TheBIccountant.com -- How to integrate M-code into your solution -- Check out more PBI- learning resources here
12 Replies
- v-huizhn-msftMicrosoft Employee
Hi THEG72,
After research, there is a blog discribed how to implement REST API pagination in Power Query, and similar thread for your reference.
How To Do Pagination In Power Query
Creating a loop for fetching paginated data from a REST APIBest Regards,
Angelia- THEG72Helper V
Thanks for the links Angelia,
I managed to get most of the code working on my version...but i ended up with an error at the List.Union step.
Here is the error message: 'Expression.Error: We cannot convert the value "http://localhost:808..." to type List."
List Union Step returns an error
The previous step returns the pages which i tested and work fine in a browser...BUT Does the list values themselves shown below need to be in quotes? like so "http://localhost:8080......" in the list so the List.Union step works?
Here is my code to date:
let
BaseUrl = "http://localhost:8080/AccountRight/Fileid/GeneralLedger/JournalTransaction/$top=1000",
EntitiesPerPage = 1000,GetJson = (Url) =>
let RawData = Web.Contents(Url),
Json = Json.Document(RawData)
in Json,GetTotalEntities = () =>
let Json = Json.Document(Web.Contents("http://localhost:8080/AccountRight/filed/GeneralLedger/JournalTransaction/")),
Items = Json[Count]
in
Items,GetPage = (Index) =>
let Skip = "$skip=" & Text.From(Index * EntitiesPerPage),
Url = BaseUrl & "&" & Skip
in Url,EntityCount = List.Max({EntitiesPerPage, GetTotalEntities()}),
PageCount = Number.RoundUp(EntityCount / EntitiesPerPage),
PageIndices = {0 .. PageCount - 1},URLs = List.Transform(PageIndices, each GetPage(_)),
Pages = List.Transform(PageIndices, each GetPage(_)),
Entities = List.Union(Pages)
in
EntitiesWhen i look at the first entry point for the journal data it shows the first 1,000 records in the list of items, the nextpage and count which is helpful...maybe i cant use the exact method you have linked this post to however i may be able to use these variables to reference the right information required.
First Journal Entry Point for API
As i work through the applied steps, each of the steps seem to return the expected results...Entity count, page count, base URL, PageIndicies and URLs for each of required pages work...
Anyway, thanks for the information to date!
Cheers Garry
- v-huizhn-msftMicrosoft Employee
Hi THEG72,
You're welcome, it's my pleasure to help you. But I am not a expert in Power Query area. For Power Query statement, you can post the case to Power Query statement to get dedicated support.
Thanks,
Angelia
- THEG72Helper V
Just posting some additional info for others....Imke has helped me get further with this on Power Query post...
My lastest code is here...
let
BaseUrl = "http://localhost:8080/AccountRight/b912ff4a-29f0-4d2a-a93b-2a6a3200a2bf/GeneralLedger/JournalTransaction/?api-version=v2&$top=1000",
EntitiesPerPage = 1000,GetJson = (Url) =>
let RawData = Web.Contents(Url),
Json = Json.Document(RawData)
in Json,GetTotalEntities = () =>
let Json = Json.Document(Web.Contents("http://localhost:8080/AccountRight/b912ff4a-29f0-4d2a-a93b-2a6a3200a2bf/GeneralLedger/JournalTransaction/?api-version=v2")),
Items = Json[Count]
in
Items,GetPage = (Index) =>
let skip = "$skip=" & Text.From(Index * EntitiesPerPage),
Url = BaseUrl & "&" & skip
in Url,EntityCount = List.Max({EntitiesPerPage, GetTotalEntities()}),
PageCount = Number.RoundUp(EntityCount / EntitiesPerPage),
PageIndices = {0 .. PageCount - 1},URLs = List.Transform(PageIndices, each GetPage(_)),
Pages = List.Transform(URLs, each GetJson(_))
in
PagesI now end up with a list of 10 records which look to hold the right information for the 10,000 records.
List.Transform
How do i get the Items List (contain each set of 1,000 records)..? by manually expanding each record and then item list with data....How do i go back to get the 2nd to 10th records table data?
Expanded first set of 1,000 records