fix: prevent duplicate alias in --empty mode for inline ref/source#1397
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fix: prevent duplicate alias in --empty mode for inline ref/source#1397
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DatabricksRelation inherited require_alias=True from BaseRelation, causing render_limited() to inject a _dbt_limit_subq_* alias that conflicts with user-provided AS aliases when running dbt run --empty. Databricks SQL does not require subquery aliases, so require_alias should be False. Resolves dbt-labs/dbt-adapters#660 for Databricks.
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tejassp-db
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Apr 15, 2026
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Summary
require_alias: bool = FalseonDatabricksRelation, preventingrender_limited()from injecting a_dbt_limit_subq_*alias that conflicts with user-providedASaliases when runningdbt run --empty--emptymode (BaseTestEmptyandBaseTestEmptyInlineSourceRef)render_limited()output has no trailing subquery aliasContext
When
dbt run --emptyis used, dbt wrapsref()andsource()in a zero-row subquery.BaseRelationdefaults torequire_alias=True, which appends an auto-generated alias (_dbt_limit_subq_{table}). If the user also has anASalias in their SQL (e.g.{{ ref('orders') }} AS orders), the two aliases conflict and produce invalid SQL.Databricks SQL does not require subquery aliases, so
require_aliasshould beFalse.Resolves dbt-labs/dbt-adapters#660 for Databricks.
Test plan
test_render_limited_with_empty_no_alias— assertsrender_limited()produces no trailing alias withlimit=0TestDatabricksEmptyInlineSourceRef— end-to-end against live cluster,dbt run --emptywith inline source aliasTestDatabricksEmpty— general--emptyconformance