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Medium severitydata flow

Power BI Refresh Error:
DF-Executor-StringValueNotInQuotes

What does this error mean?

A string literal in a data flow expression is not enclosed in single quotes. ADF's expression language requires all string constants to be single-quoted — an unquoted word in a Derived Column, filter, or join condition is interpreted as a column reference rather than a string value, causing this parse error.

Common causes

  • 1A string constant in a filter or Derived Column expression is written without quotes — for example, `status == active` instead of `status == 'active'`
  • 2An expression was copied from a tool or language that uses double quotes (Python, SQL, JavaScript) and the quotes were not converted to single quotes for ADF expression syntax
  • 3A pipeline parameter is interpolated into an expression string in a way that produces a bare word when the parameter value contains certain characters
  • 4A conditional expression compares a column against a hardcoded value that was typed without quotes in the ADF expression builder

How to fix it

  1. 1Open the failing expression in the ADF data flow expression builder and locate the string literal that is missing its surrounding single quotes.
  2. 2In ADF data flow expressions, string literals must be enclosed in single quotes — for example, use `'active'` not `active`.
  3. 3If the string value is sourced from a pipeline parameter, verify the parameter is passed as a string type and the expression wraps it correctly.
  4. 4Use the expression builder 'Refresh' button to validate the expression syntax before saving.
  5. 5Enable debug mode to step through the failing transformation and confirm the expression evaluates correctly with actual data.

Frequently asked questions

Why do ADF expressions use single quotes instead of double quotes?

ADF data flow expressions use Spark syntax, where single quotes are string literals and double quotes are not valid — a common source of confusion for developers coming from SQL or Python where both are accepted.

How do I find which expression is missing the quotes?

The error message includes the transformation name. Open it in ADF Studio and look for bare words that should be strings — unquoted comparisons like `status == active` instead of `status == 'active'` are the most common cause.

What if I need to include a single quote inside a string value?

Escape single quotes by doubling them: `'it''s correct'`. Alternatively, use `toString()` before comparison. Most ADF filter expressions can be rewritten to avoid embedded quotes entirely.

Will downstream Power BI datasets be affected?

Yes — the data flow fails immediately without processing any data. Dependent datasets and reports serve stale figures until the expression is fixed.

Official documentation: https://learn.microsoft.com/en-us/azure/data-factory/data-flow-troubleshoot-guide

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