SQL Fundamentals || Oracle SQL语言   SQL Fundamentals: Using Single-Row Functions to Customize Output使用单行函数自定义输出 SQL Fundamentals || Single-Row Functions || 字符函数 character functions SQL Fundamentals || Single-Row Functions || 数字函数number functions SQL F…

SQL Fundamentals || Oracle SQL语言   SQL Fundamentals: Using Single-Row Functions to Customize Output使用单行函数自定义输出 SQL Fundamentals || Single-Row Functions || 字符函数 character functions SQL Fundamentals || Single-Row Functions || 数字函数number functions SQL F…

SQL Fundamentals || Oracle SQL语言 SQL Fundamentals: Using Single-Row Functions to Customize Output使用单行函数自定义输出 SQL Fundamentals || Single-Row Functions || 字符函数 character functions SQL Fundamentals || Single-Row Functions || 数字函数number functions SQL Fun…

prototype是向对象中添加属性和方法,返回对象类型原型的引用,例如对js中日期函数Date进行扩展: Date.prototype.Format = function (fmt) { var o = { "M+": this.getMonth() + 1, //月份 "d+": this.getDate(), //日 "h+": this.getHours(), //小时 "m+": this.getMinutes(),…

参考资料:http://docs.oracle.com/database/122/SQLRF/Functions.htm#SQLRF006 Single-row functions return a single result row for every row of a queried table or view. These functions can appear in select lists, WHEREclauses, START WITH and CONNECT BY clause…

SQL Fundamentals || Oracle SQL语言   SQL Fundamentals: Using Single-Row Functions to Customize Output使用单行函数自定义输出 SQL Fundamentals || Single-Row Functions || 字符函数 character functions SQL Fundamentals || Single-Row Functions || 数字函数number functions SQL F…

SQL Fundamentals || Oracle SQL语言 DUAL is a public table that you can use to view results from functions and calculations. The DUAL table is owned by the user SYS and can be accessed by all users. It contains one column, DUMMY, and one row with the va…

SQL Fundamentals || Oracle SQL语言 SQL Fundamentals: Using Single-Row Functions to Customize Output使用单行函数自定义输出 SQL Fundamentals || Single-Row Functions || 字符函数 character functions SQL Fundamentals || Single-Row Functions || 数字函数number functions SQL Fun…

对于SQL语言,有两个组成部分: DML(data manipulation language) 它们是SELECT.UPDATE.INSERT.DELETE,就象它的名字一样,这4条命令是用来对数据库里的数据进行操作的语言. DDL(data definition language) DDL比DML要多,主要的命令有CREATE.ALTER.DROP等,DDL主要是用在定义或改变表(TABLE)的结构,数据类型,表之间的链接和约束等初始化工作上,他们大多在建立表时使用. 当发生了任何DDL操作…

获取当前UNIX时间戳函数: unix_timestamp语法: unix_timestamp() 返回值: bigint说明: 获得当前时区的UNIX时间戳举例: hive> select unix_timestamp() from dual; OK Time taken: row(s) 日期函数UNIX时间戳转日期函数: from_unixtime 语法:from_unixtime(bigint unixtime[, string format]) 返回值: string说明: 转化UNIX…