1、概述
1.1 标识符无效
- 保留字（reserved = ‘Y’）是不能被用作 列名 的
- 关键字（reserved = ‘N’）虽然可以用作 列名，但Oracle 并不建议。
SELECT t.reserved FROM v$reserved_words t WHERE t.keyword = 'DESC';
RESERVED
Y
2、数据字典 v$reserved_words
Oracle 12c - 官方文档 - v$reserved_words 详解
| Column | Description | 理解 |
|---|---|---|
| KEYWORD | Name of the keyword | |
| LENGTH | Length of the keyword | |
| RESERVED | Indicates whether the keyword cannot be used as an identifier (Y) or whether the keyword is not reserved (N) | |
| RES_TYPE | Indicates whether the keyword cannot be used as a type name (Y) or whether the keyword is not reserved (N) |
|
| RES_ATTR | Indicates whether the keyword cannot be used as an attribute name (Y) or whether the keyword is not reserved (N) |
|
| RES_SEMI | Indicates whether the keyword is not allowed as an identifier in certain situations, such as in DML (Y) or whether the keyword is not reserved (N) | |
| DUPLICATE | Indicates whether the keyword is a duplicate of another keyword (Y) or whether the keyword is not a duplicate (N) |
