title: What to try to get BigQuery to CAST BYTES to STRING?
body: <p>BigQuery <a href="https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators" rel="noreferrer">Standard SQL documentation</a> suggests that BYTE fields can be coerced into STRINGS. </p>
  
  <p>We have a byte field that is the result of SHA256 hashing a field using BigQuery itself. </p>
  
  <p>We now want to coerce it to a STRING, yet when we run "CAST(field_name to STRING)" we get an error: </p>
  
  <blockquote>
    <p>Query Failed Error: Invalid cast of bytes to UTF8 string</p>
  </blockquote>
  
  <p>What is preventing us from getting a string from this byte field? Is it surmountable? If so, what is the solution?</p>