SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Function JSONExtract (alias a) (children 1)
     ExpressionList (children 3)
      Literal \'{"a":"123456.123456"}\'
      Literal \'a\'
      Literal \'Decimal(20, 4)\'
    Function toTypeName (children 1)
     ExpressionList (children 1)
      Identifier a