What causes UNRESOLVED_FIELD?

A nested struct field was accessed with the wrong path, e.g. col.subfield.missing instead of col.subfield.correct. The source JSON or Parquet file has a different nested schema than the query expects. A schema evolution event added or renamed a nested field without updating dependent queries. The struct column was dropped and recreated with a different field layout. Case sensitivity mismatch between the field name in the query and the actual field name in the schema

How do I fix UNRESOLVED_FIELD?

Run SELECT schema_of_json(to_json(struct_col)) or DESCRIBE TABLE to inspect the exact nested schema.. Use backtick quoting for field names that contain special characters: col.`field-name`.. Check case sensitivity settings — set spark.sql.caseSensitive=true to diagnose case mismatches.. Update the query to match the current field path after schema evolution.. For JSON strings, use get_json_object(col, '$.nested.field') as a more resilient alternative to struct access.

Medium severitysql

Power BI Refresh Error:
UNRESOLVED_FIELD

What does this error mean?

Spark SQL could not resolve a nested field or struct attribute referenced in the query. The field name does not exist at the specified nesting level, or the struct column itself does not exist in the schema.

Common causes

1A nested struct field was accessed with the wrong path, e.g. col.subfield.missing instead of col.subfield.correct
2The source JSON or Parquet file has a different nested schema than the query expects
3A schema evolution event added or renamed a nested field without updating dependent queries
4The struct column was dropped and recreated with a different field layout
5Case sensitivity mismatch between the field name in the query and the actual field name in the schema

How to fix it

1Run SELECT schema_of_json(to_json(struct_col)) or DESCRIBE TABLE to inspect the exact nested schema.
2Use backtick quoting for field names that contain special characters: col.`field-name`.
3Check case sensitivity settings — set spark.sql.caseSensitive=true to diagnose case mismatches.
4Update the query to match the current field path after schema evolution.
5For JSON strings, use get_json_object(col, '$.nested.field') as a more resilient alternative to struct access.

Frequently asked questions

Is UNRESOLVED_FIELD the same as UNRESOLVED_COLUMN?

They are related but distinct. UNRESOLVED_COLUMN refers to a top-level column not found in any table in scope. UNRESOLVED_FIELD refers specifically to a nested field within a struct or complex type.

How do I access all fields of a struct without knowing their names?

Use col.* in Databricks SQL to expand a struct into individual columns. This avoids hardcoded field names that break on schema change.