public class Solution { public static void main(String[] args) { long positiveSide = 0; long negativeSide = 0; int side; for(long i = 0; i < 1000000; i++) { side = (int)(Math.random() * 2); if(side == 1) positiveSide++; else negativeSide++; } System.…
Coordinate Systems Projected Coordinate Systems This is an archive of a previous version of the ArcGIS REST API. The current version can be found at http://resources.arcgis.com/en/help/arcgis-rest-api/. Well-known ID Name 2000 Anguilla_1957_British_W…
大致分为两种情况:ID连续和ID不连续. 1.ID连续的情况: 2.ID不连续的情况: (1).两次对表查询,效率较低. ID from A) (2).外层查询没有对表A进行查询,效率提高. ID from A order by ID) as a order by a.ID desc (3).ROW_NUMBER()函数效率更高,SQL2005以上版本可用. 以上是自己做的笔记,学习过程中,好记性不如烂笔头,自己也记录下来,作为成长的一部分.…