What causes UNSUPPORTED_SUBQUERY_EXPRESSION_CATEGORY?

Correlated subquery in a SELECT list that references multiple outer columns in an unsupported combination. Subquery inside an IN clause that also references an outer-query column (non-equi correlated IN). Scalar subquery that returns more than one column. Subquery in an aggregate function argument. LATERAL subquery pattern not supported in the current Databricks Runtime version

How do I fix UNSUPPORTED_SUBQUERY_EXPRESSION_CATEGORY?

Rewrite correlated subqueries as JOINs or LEFT JOINs with aggregate subqueries in the ON or USING clause. Replace IN (subquery) with EXISTS or a JOIN to gain more control over correlation. Materialise the subquery as a CTE (WITH clause) and then join to it. For window-function alternatives, use PARTITION BY to replicate correlated aggregation. Check the Databricks Runtime release notes — some correlated subquery patterns were added in later versions

Medium severityquery

Power BI Refresh Error:
UNSUPPORTED_SUBQUERY_EXPRESSION_CATEGORY

What does this error mean?

A subquery was used in a position or with a pattern that Spark SQL does not support. This commonly occurs with correlated subqueries that reference outer-query columns in unsupported ways.

Common causes

1Correlated subquery in a SELECT list that references multiple outer columns in an unsupported combination
2Subquery inside an IN clause that also references an outer-query column (non-equi correlated IN)
3Scalar subquery that returns more than one column
4Subquery in an aggregate function argument
5LATERAL subquery pattern not supported in the current Databricks Runtime version

How to fix it

1Rewrite correlated subqueries as JOINs or LEFT JOINs with aggregate subqueries in the ON or USING clause
2Replace IN (subquery) with EXISTS or a JOIN to gain more control over correlation
3Materialise the subquery as a CTE (WITH clause) and then join to it
4For window-function alternatives, use PARTITION BY to replicate correlated aggregation
5Check the Databricks Runtime release notes — some correlated subquery patterns were added in later versions

Frequently asked questions

Does Databricks support correlated subqueries at all?

Yes — Databricks supports many correlated subquery patterns, particularly simple equi-correlated EXISTS and scalar subqueries. Complex multi-column correlations and non-equi correlations in IN clauses have more restrictions.