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msturzen's avatar
msturzen
Frequent Visitor
1 month ago
Solved

GraphQL update... mutation for Fabric SQL DB failing

Hi everybody,  I want to update items in a Fabric SQL DB via GraphQL mutation query. But that fails with "InternalServerError" (and nothing else).  What I tried:  ❌ mutation update.... ✅ mutatio...
API for GraphQL
data engineering
  • msturzen's avatar
    msturzen
    14 days ago

    Hi everyone, 

    After corresponding with MSFT support team I got some feedback and insights. Summing it up here hoping it might be useful to others some time. (This is the result as of Sept. 16th 2026)

    On the traces support found the following error message: "The target table 'dbo.table' of the DML statement cannot have any enabled triggers if the statement contains an OUTPUT clause without INTO clause."

    1. Addtional bit of info, that I stripped initially since I didn't think it could be the culprit 😯:
      The table used has an update trigger (updates the updated_at column)
    2. Fabric's GraphQL engine generates an UPDATE ... OUTPUT ... SQL statement (without an INTO clause)
      This is done (my guess) to be able to return the requested columns without an additional select after the update (update does not return the updated rows directly)
    3. SQL Server does not allow the above statement if there are enabled update triggers on the table. See: https://learn.microsoft.com/en-us/sql/t-sql/queries/output-clause-transact-sql?view=sql-server-ver17#triggers.  This is due to timing/racing and consistency issues.

     

    This leaves me with the following options: 

    • Do not use triggers:
      • Delete or disable (or do not create) them for the mutations you want to use (UPDATE trigger in my case), but then you lose the action the the trigger performs
      • If the action is necessary replace the trigger logic (possible in my case: Caller could just add a value for UPDATED_AT column, but would everyone do so?)
    • Use a stored procedure to do the update with an INTO clause using a @table_variable

     

    I'm not a big fan of either. I'd be very fond of the GraphQL implementation being changed to use the OUTPUT ... INTO ... solution suggested. It seems strange that a (imo) legitimate use of trigger is prohibited by an implementation detail of the GraphQL layer. I'm not very confident though this will land any time soon.

    I want to thank Tharun from the support team for helping.

    Best Martin

v-achippa's avatar
v-achippa
Icon for Community Support rankCommunity Support
1 month ago

Hi msturzen​,

Thank you for reaching out to Microsoft Fabric Community.

Thank you ipkus​ for the prompt response.

As we haven’t heard back from you, we wanted to kindly follow up to check if the solution provided by the user for the issue worked?  or let us know if you need any further assistance.

Thanks and regards,
Anjan Kumar Chippa

msturzen's avatar
msturzen
Frequent Visitor
1 month ago

Dear v-achippa​, 

to me there is no solution yet. All I have is a workaround for something - update of a single row in a SQL DB - that should just work out of the box. Don't get me wrong: I am thankful for the workaround.
At least - if there is some known product limitation - that should be documented in Fabric's GraphQL API documentation

Thanks
Martin

  • v-achippa's avatar
    v-achippa
    Icon for Community Support rankCommunity Support
    30 days ago

    Hi msturzen​,

    Thank you for the clarification. Glad to hear that the issue is resolved now. We appreciate you sharing your feedback regarding the documentation and the workaround.

    Thanks and regards,
    Anjan Kumar Chippa

    • msturzen's avatar
      msturzen
      Frequent Visitor
      30 days ago

      Hi v-achippa​, 

      sorry if I come over as nitty-picky: My previous reply started with "... there is no solution ..."
      I don't understand how you come to the conclusion the issue is resolved. To me this looks like a flaw/bug/defect/issue in Fabric's GraphQL implementation. 
      I think I provided minimal code samples to be able to reproduce the behaviour or point me at something I did wrong.

      Looking forward to hear back from you.

      Best
      Martin

      • v-achippa's avatar
        v-achippa
        Icon for Community Support rankCommunity Support
        29 days ago

        Hi msturzen​,

        Thank you for the clarification. You are correct that the stored procedure is only a workaround and does not resolve the original issue.

        • Based on the repro you provided, the updateproduct mutation is failing with an InternalServerError, while the corresponding sql update works successfully. Since update mutations are supported for fabric sql databases, this behaviour is not expected.

        I recommend please raise a Microsoft support ticket and provide all the required details including the request/operation details for one of the failed requests.

        Create a Fabric and Power BI Support Ticket - Power BI | Microsoft Learn

        Thanks and regards,
        Anjan Kumar Chippa