title: Rename all column names for joining purpose in big query
body: <p>I need to join two tables with exactly the same column names. I will need to rename the columns before the joining step. <strong>Each table contains 100+ columns.</strong> I wonder if there's any way to add prefix or suffix to rename all the columns, rather than manually change them with <code>AS</code>. I'm using standard SQL on BigQuery. I put an example in below for illustration. I wonder if there's any function in BigQuery like: </p>
  
  <pre><code>UPDATE
    inv
  SET
    CONCAT(column_name, '_inv') AS column_name
  </code></pre>
  
  <p>... example ... thank you in advance! </p>
  
  <pre><code>WITH
    inv AS (
    SELECT
      '001' AS company,
      'abc' AS vendor,
      800.00 AS transaction,
      'inv' AS type
    UNION ALL
    SELECT
      '002' AS company,
      'efg' AS vendor,
      23.4 AS transaction,
      'inv' AS type ),
    prof AS (
    SELECT
      '001' AS company,
      'abc' AS vendor,
      800.00 AS transaction,
      'prof' AS type
    UNION ALL
    SELECT
      '002' AS company,
      'efg' AS vendor,
      23.4 AS transaction,
      'prof' AS type )
  SELECT
    inv.*,
    prof.*
  FROM
    inv
  FULL JOIN
    prof
  USING
    (company,
      vendor,
      transaction)
  </code></pre>