title: List of reserved words for Google BigQuery legacy syntax
body: <p>I found the list of reserved keywords for Standard SQL, at <a href="https://cloud.google.com/bigquery/docs/reference/standard-sql/lexical#reserved-keywords" rel="nofollow noreferrer">Standard SQL Lexical Structure - Lexical Structure - Reserved Keywords</a>.</p>
  
  <p>But I can't find the equivalent list for Legacy SQL, although there is a reference to it at <a href="https://cloud.google.com/bigquery/docs/reference/legacy-sql" rel="nofollow noreferrer">Legacy SQL Functions and Operators - Query Syntax - SELECT Clause</a>:</p>
  
  <blockquote>
    <p>You can use square brackets to escape reserved words so that you can use them as field name and aliases. For example, if you have a column named "prefix", which is a reserved word in BigQuery syntax, the queries referencing that field will fail with obscure error messages unless you escape it with square brackets</p>
  </blockquote>
  
  <p>I know some of the keywords are different; for example Legacy SQL has <code>FLATTEN</code> which I assume is reserved, which Standard SQL does not.</p>
  
  <p>Any pointers would help.</p>