oracle从入门到精通:原文信息Oracle从入门到精通一、SQL...........................................................................................................................................................81.1、基本概念:...................................................................................................................................81.2、数据库安全:...............................................................................................................................81.3、基本的SQLSELECT语句.............................................................................................................81.4、SELECT语句...................................................................................................................................91、语法:.......................................................................................................................................92、SQL语句说明:.........................................................................................................................93、数字和日期都可以使用数学运算符建立表达式。...............................................................94、定义空(NULL)值...................................................................................................................95、别名...........................................................................................................................................96、spool+路径...........................................................................................................................107、连接操作符:||...................................................................................................................108、文本字符串.............................................................................................................................109、DISTINCT.................................................................................................................................101.5、SQLPLUS与SQL的关系...........................................................................................................101、SQLPLUS命令的功能:...........................................................................................................102、查询SQLPLUS命令...............................................................................................................103、SQLPLUSW在WINDOWS下运行的分析器。.........................................................................104、SQLPLUS命令:.....................................................................................................................111.6、单行函数.....................................................................................................................................121、character字符类型函数:...................................................................................................122、number数字类型函数.............................................................................................................153、时间类型函数:(date).......................................................................................................151.7、嵌套函数:....................................................................................................................................