ORACLE伪列探究

ORACLE官方文档给出的伪列

http://docs.oracle.com/cd/E11882_01/server.112/e41084/pseudocolumns.htm#SQLRF0025

pseudocolumn behaves like a table column, but is not actually stored in the table. You can select from pseudocolumns, but you cannot insert, update, or delete their values. A pseudocolumn is also similar to
a function without arguments (refer to Chapter 5, "Functions"). However, functions
without arguments typically return the same value for every row in the result set, whereas pseudocolumns typically return a different value for each row.

This chapter contains the following sections:

-->Hierarchical Query Pseudocolumns

-->Sequence Pseudocolumns

-->Version Query Pseudocolumns

-->COLUMN_VALUE Pseudocolumn

-->OBJECT_ID Pseudocolumn

-->OBJECT_VALUE Pseudocolumn

-->ORA_ROWSCN Pseudocolumn

-->ROWID Pseudocolumn

-->ROWNUM Pseudocolumn

-->XMLDATA Pseudocolumn

具体可去官网查看~