文件名称：命名习惯-SQL语言基础
文件大小：5.26MB
文件格式：PPT
更新时间：2024-05-15 13:25:07
SQL 基础
命名习惯 * 必须以一个字母开始 可以是1-10个字符的长度 仅能包括字符： A–Z, a–z, 0–9, _, $, 和# 不能与本用户拥有的其他对象重名 不能是一个 Oracle服务器的保留字 * Naming Rules Name database tables and columns according to the standard rules for naming any Oracle database object: Table names and column names must begin with a letter and can be 1–30 characters long. Names must contain only the characters A–Z, a–z, 0–9, _ (underscore), $, and # (legal characters, but their use is discouraged). Names must not duplicate the name of another object owned by the same Oracle Server user. Names must not be an Oracle Server reserved word. Naming Guidelines Use descriptive names for tables and other database objects. Name the same entity consistently in different tables. For example, the department number column is called DEPTNO in both the EMP table and the DEPT table. Note: Names are case insensitive. For example, EMP is treated as the same name as eMP or eMp. For more information, see Oracle Server SQL Reference, Release 8, “Object Names and Qualifiers.”