SQL语言简介





1、　　SQL概述

SQL是一种面向数据库的通用数据处理语言规范，能完成以下几类功能：提取查询数据，插入修改删除数据，生成修改和删除数据库对象，数据库安全控制，数据库完整性及数据保护控制。

数据库对象包括表、视图、索引、同义词、簇、触发器、函数、过程、包、数据库链、快照等（表空间、回滚段、角色、用户）。数据库通过对表的操作来管理存储在其中的数据。

-a brief SQL language. SQL outlined SQL oriented databases is a common data-processing language and function can be completed the following categories : Inquiries data extraction, insert amendments to delete data, generate change and delete database objects, database security control. Database integrity control and data protection. Database objects including tables, views, indexes, synonyms, clusters, triggers, functions, processes, packages, database chain, Shots etc. (Table space Rollback Segment, the role of users). Database on the operating table to manage stored in the data.