Forum Discussion

berta2b's avatar
berta2b
Helper I
10 years ago

Call a REST API multiple times using Power Query

  I am loading a Data Model using Power Query via a RESTful API call returning JSON data so when you look at the code generated it's something like   let  Source = Json.Document(Web.Contents("htt...
bidgeir's avatar
bidgeir
Most Valuable Professional
10 years ago

You can create a function from your query using this syntax:

let functionName = (param1 as datatype) =>

let

 Source = Json.Document(Web.Contents("https:// MY API CALL" & param1).

in

 Source

in functionName

 

You can then create a table with your parameters and then add a custom column to your table that calls/invokes your function

 

You can see an example here http://datachix.com/2014/05/22/power-query-functions-some-scenarios/ and here http://satalyst.com/power-query-creating-a-parameterized-function-in-m/

  • Vitaliy's avatar
    Vitaliy
    Helper I
    7 years ago

    Hi 2 all and sorry for my English!


    I have a question that has been torturing for 2 days already. I have a table MYTABLE with 2 columns (URL and Index)of the form:

     

    URL                                                                                                    Index

    jira.test.com/rest/api/2/issue/MYPROJECTKEYNAME-10/worklog    0

    jira.test.com/rest/api/2/issue/MYPROJECTKEYNAME-11/worklog    1

    ..................................................                                                                   1999 

     

    In this table I have 2000 records. My goal is to get the data stored in these URLs.

    For this I use the following command:

    #"MyNewTable"= Table.AddColumn(#"MYTABLE", "DataFromURLsColumn", each Json.Document(Web.Contents(#"MYTABLE"{[Index]}[URL])))

     

    , but this request is very difficult and takes a very long time. So I must wait approximately 20-30 minutes or more.

    My questions is next:

    1. Is there a faster way to get this data stored in the URL?
    2. Perhaps there are some global or other settings in the Power BI?
    3. Does this command work so slowly due to the number of queries to jira rest api, or maybe because I'm adding a new calculated column to the table?
    I will be very grateful for any help, thank you in advance!

  • jan_k123's avatar
    jan_k123
    Frequent Visitor
    7 years ago

    Hi bidgeir berta2b 

    Thanks for this solution.

    I got it working feeding off a REST API service. Then I wanted it to be scheduled on Power BI Service. But got this error:

    Query contains unsupported function. Function name: Web.Contents

     

    I have used 2 parameters:  (start as text, count as text) => 

    Then I applied this against a list:  = List.Generate(()=>0, each _ < 67000, each _ + 1000) 

    In a new query i start a custom function with Column1 = the List function and Column2 = 1000. After that I add the web-query which has the start and count params. 

    The result should be it gets 1000 records at a time, otherwise it fails/time-out. 

     

    Can you help me with the web-query refresh on PBI Service? (I am using basic auth with user and pass)

    Thanks!