feat(duckdb): transpile BigQuery IN UNNEST(array) to ARRAY_CONTAINS#7892
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…TAINS BigQuery uses `value IN UNNEST(array_expr)` to test array membership. DuckDB has no `UNNEST` in this position but provides `ARRAY_CONTAINS`. The transpilation wraps the result in `COALESCE(..., FALSE)` to handle NULL arrays safely — `ARRAY_CONTAINS(NULL, x)` returns NULL in DuckDB, but BigQuery's `IN UNNEST(NULL)` returns FALSE. Adds: - `IN UNNEST(arr)` → `COALESCE(ARRAY_CONTAINS(arr, val), FALSE)` in DuckDB generator via `in_sql` override - Transpilation test for BigQuery → DuckDB
geooo109
reviewed
Jul 17, 2026
Replace COALESCE(ARRAY_CONTAINS(arr, x), FALSE) with a CASE expression that preserves BigQuery's three-valued NULL semantics: - NULL IN UNNEST([1, 2]) → NULL (not FALSE) - 3 IN UNNEST([1, NULL]) → NULL (not FALSE) - 1 IN UNNEST(NULL) → FALSE - 1 IN UNNEST([]) → FALSE Use expression API instead of f-string interpolation per review feedback. Add NOT IN UNNEST test case. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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@sirockin is this still a draft? What's pending? |
geooo109
marked this pull request as ready for review
July 21, 2026 11:02
geooo109
reviewed
Jul 21, 2026
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I will take it to the finish line. |
geooo109
approved these changes
Jul 23, 2026
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Summary
BigQuery uses
value IN UNNEST(array_expr)to test array membership. DuckDB has noUNNESTin this position but providesARRAY_CONTAINS.Changes
IN UNNEST(arr)→COALESCE(ARRAY_CONTAINS(arr, val), FALSE)in DuckDB generator viain_sqloverrideCOALESCE(..., FALSE)for null safety —ARRAY_CONTAINS(NULL, x)returns NULL in DuckDB, but BigQuery'sIN UNNEST(NULL)returns FALSEMotivation
We use sqlglot to transpile BigQuery SQL models to DuckDB for local testing via sqlmesh.
IN UNNEST(...)is used in several of our production models for array membership checks but was not previously transpiled to DuckDB.