SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 3)
    Identifier message
    Identifier key
    Function hex (alias hmac_hex) (children 1)
     ExpressionList (children 1)
      Function HMAC (children 1)
       ExpressionList (children 3)
        Literal \'sha256\'
        Identifier message
        Identifier key
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier hmac_test
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier message
