Access Query Error: "Cannot define field more than once"

Chan 49 0 Reputation points
2025-08-11T00:17:18.0033333+00:00

When running a query in Access, an error message appears stating, "Cannot define field more than once." Despite reviewing the field titles and finding no duplicates, guidance is needed on how to identify which field is causing the issue. What steps can be taken to troubleshoot this error?

Microsoft 365 and Office | Access | For business | Windows
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  1. Duane Hookom 26,435 Reputation points Volunteer Moderator
    2025-08-11T00:21:02.6333333+00:00

    Can you post the SQL view of your query? Are there source queries referenced in your current query? Can you create a new similar query without issues?

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  2. Dora-T 4,105 Reputation points Microsoft External Staff Moderator
    2025-08-11T02:42:00.6133333+00:00

    Hi @Chan 49

    Thank you for reaching out to the Microsoft Q&A Forum regarding the error you are seeing in Access.

    Based on my research, this error message can sometimes appear when there are duplicate field names in the query output, such as when two fields share the same name, even if they come from different tables.

    Could you please share the SQL for your query and, if possible, a screenshot of the query design or SQL View (please make sure to hide any personal or sensitive information)? That would help me get a better understanding of the situation so we can go through it together and check if there might be any areas where duplication is occurring. 

    Please understand that our initial reply may not always immediately resolve the issue. However, with your help and more detailed information, we can work together to find a solution. 

    I look forward to hearing back from you and helping you get this resolved. 

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  3. DBG 11,456 Reputation points Volunteer Moderator
    2025-08-12T16:17:21.35+00:00

    Hi Chan 49, as others have requested, please show us your SQL statement, so we can try to help you further. Thank you.

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  4. Chan 49 0 Reputation points
    2025-08-12T17:28:43.1966667+00:00

    I finally got into the design view and found the repeated field.


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