用法 sql语句 SELECT AUTHOR.FIRST_NAME, AUTHOR.LAST_NAME, COUNT(*) FROM AUTHOR JOIN BOOK ON AUTHOR.ID = BOOK.AUTHOR_ID WHERE BOOK.LANGUAGE = 'DE' AND BOOK.PUBLISHED > DATE '2008-01-01' GROUP BY AUTHOR.FIRST_NAME, AUTHOR.LAST_NAME ORDER BY AUTHOR.LAST_NAME…
C++版例子: https://lorensen.github.io/VTKExamples/site/Cxx/PolyData/SelectVisiblePoints/ 优点: Simple to use Can be implemented easily in object or image sapce Can be executed quickly, even with many polygons 缺点 Takes up a lot of memory Can't do transpare…
在 Shell 语言中,经常会看到中括号和括号组成的特殊标识,例如:[].[[]].(()).$(()).().这些符号经常使我们非常迷惑,弄清楚它们之间的作用和区别非常必要. 在开始之前,我们先来学习一个 test 命令. test命令 test 命令主要是用来做表达式的判断,其语法结构如下: 1 test {EXPRESSION} 例如: 1234 if test "a" == "a"then echo match! fi [] 其实 [] 符号的作用与 tes…