SelectWithUnionQuery (children 2)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function CAST (alias ndb) (children 1)
     ExpressionList (children 2)
      Identifier database
      Literal \'Nullable(String)\'
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.tables
   Function like (children 1)
    ExpressionList (children 2)
     Identifier ndb
     Literal \'%\'
 Identifier Null
