Attach Diagnostic to "duplicate table name" error

Is your feature request related to a problem or challenge?

For a query like:

SELECT * FROM users a, users a

The only message that the end user of an application built atop of DataFusion sees is:

Schema error: Schema contains duplicate qualified field name a.id

Similarly, for:

WITH cte AS (SELECT 1 AS col), cte AS (SELECT 2 AS col) SELECT 1

We get:

Error during planning: WITH query name "cte" specified more than once

We want to provide a richer message that references and highlights locations in the original SQL query, and contextualises and helps the user understand the error. In the end, it would be possible to display errors in a fashion akin to what was enabled by #13664 for some errors:

See #14429 for more information.

Describe the solution you'd like

Attach a well crafted Diagnostic to the DataFusionError, building on top of the foundations laid in #13664. See #14429 for more information.

Describe alternatives you've considered

No response

Additional context

No response

I think this is a good first issue as the need is clear and the tests in https://github.com/apache/datafusion/blob/85fbde2661bdb462fc498dc18f055c44f229604c/datafusion/sql/tests/cases/diagnostic.rs are well structured for extension.

take

@zjregee

Hey @zjregee how is it going with this ticket :) Can I help with anything?

Sorry for the delay, I will start and finish it in the next few days.

Take

DFParser::parse_sql(query) returns an Ok for both examples in the OP 🤔 Did something change in the meantime to allow these ambiguous references or am I missing something?

My test is

#[test]
fn test_ambiguous_with_diagnostic() -> Result<()> {
    // let query = "SELECT * FROM users a, users a";
    let query = "WITH cte AS (SELECT 1 AS col), cte AS (SELECT 2 AS col) SELECT 1";
    let spans = get_spans(query);
    match DFParser::parse_sql(query) {
        Ok(stmts) => {
            panic!("expected error, got {:?}", stmts);
        }
        Err(err) => match err.diagnostic() {
            Some(diag) => {
                let diag = diag.clone();
                assert_snapshot!(diag.message, @"TODO");
                Ok(())
            }
            None => {
                panic!("expected diagnostic")
            }
        },
    }
}

Hi, I'd like to work on this. First-time contributor — will follow the pattern from PR #15209.

feat: attach Diagnostic to duplicate CTE name error

The latest related PR is #20720 which had review feedback that was not yet addressed.
I can pick it up and try addressing reviewer's feedback.

take

feat: attach Diagnostic to duplicate table name errors

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Attach `Diagnostic` to "duplicate table name" error #14436

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Attach Diagnostic to "duplicate table name" error #14436

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Is your feature request related to a problem or challenge?

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Describe alternatives you've considered

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alamb commented on Feb 4, 2025

zjregee commented on Feb 5, 2025

eliaperantoni commented on Feb 13, 2025

zjregee commented on Feb 17, 2025

vegarsti commented on Jul 28, 2025

vegarsti commented on Jul 29, 2025

amitvijapur commented on Apr 6, 2026

haochunchang commented on Oct 8, 2026

haochunchang commented on Oct 8, 2026

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Attach `Diagnostic` to "duplicate table name" error #14436