随着UNIX各种衍生版本不断发展壮大,标准化工作就十分必要.其实干啥事都是这样,玩的人多了,必须进行标准化. 一.UNIX标准 1.1 ISO C(ANSI C) ANSI:Amerocan Natoinal Standards Institute,美国国家标准学会,是ISO的程序 ISO: International Organization for Standardization,国际标准化组织 IEC:International Electrotechnical CCommission,国…
OpenCASCADE Conic to BSpline Curves-Hyperbola eryar@163.com Abstract. Rational Bezier Curve can represent conic curves such as circle, ellipse, hyperbola, .etc. But how to convert a conic curve to BSpline curve is still question, i.e. Represent a con…
摘自:http://www.cnblogs.com/linjiqin/category/283838.html oracle decode用法 select decode( x , 1 , ‘x is 1’, 2 , ‘x is 2’, ‘others’) from dual 当x等于1时,则返回‘x is 1’. 当x等于2时,则返回‘x is 2’. 否则,返回‘others’. Oracle序列号详解 例1:创建序列:CREATE SEQUENCE ABC INCREMENT BY 1 S…
常用Oracle函数 SQL中的单记录函数 1.ASCII 返回与指定的字符对应的十进制数; SQL> select ascii('A') A,ascii('a') a,ascii('0') zero,ascii(' ') space from dual; A A ZERO SPACE --------- --------- --------- --------- 65 97 48 32 2.CHR 给出整数,返回对应的…
SQL中的单记录函数 1.ASCII返回与指定的字符对应的十进制数;SQL> select ascii('A') A,ascii('a') a,ascii('0') zero,ascii(' ') space from dual; A A ZERO SPACE--------- --------- --------- --------- 65 97 48 32 2.CHR给出整数,返回对应的字符;SQL>…