SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 3)
    Function concat (alias haystack) (children 1)
     ExpressionList (children 2)
      Function unhex (children 1)
       ExpressionList (children 1)
        Literal \'00\'
      Literal \' key="v" \'
    Function length (children 1)
     ExpressionList (children 1)
      Identifier haystack
    Function extract (alias needle) (children 1)
     ExpressionList (children 2)
      Identifier haystack
      Literal \'key="(.*?)"\'