atitit.判断时间重叠方法总结 java c++ c#.net js php
2. 重叠算法 实际上就是日期集合跟个时间集合的的交集(乘法算法) 1
1. 判断时间重叠具体流程思路
先判断日期重叠，在判断时间区段重叠。
每个区段都有内包含，外包含，左包含，右包括...所以,or表达式需要4*4=16个..每个or 表达式包括4个and表达式( 两个日期表达式,两个时间范围表达式)
最终的最终的的表达式需要16*4=64个,,比较长的了..
作者:: 老哇的爪子 Attilax 艾龙， EMAIL:1466519819@qq.com
转载请注明来源： http://blog.csdn.net/attilax
2. 重叠算法 实际上就是日期集合跟个时间集合的的交集(乘法算法)
在程序设计里有。。。。。
回答
那实际上就是交、并、差。
所谓加，实际上就是求两个集合的并集
减，就是求两个集合的差集
乘，就是求两个集合的并集
它们都是从逻辑的运算推出来的
另外更正一下：乘是求两个集合的交集。
3. 代码---
private void ini() {
String db_start_fld = "start_time";
String db_end_fld = "end_time";
String db_include_exp = "db_start_fld>=ui_start and db_end_fld<=ui_end ";
String db_outclude_exp = "db_start_fld<=ui_start and db_end_fld>=ui_end ";
String db_leftinclude_exp = "db_end_fld>=ui_start and db_end_fld <=ui_end ";
String db_ritinclude_exp = "db_start_fld>=ui_start and db_end_fld<=ui_end ";
List<String> dateExpList = new ArrayList<String>() {
{
add(expandFunc(db_include_exp));
add(expandFunc(db_outclude_exp));
add(expandFunc(db_leftinclude_exp));
add(expandFunc(db_ritinclude_exp));
}
private String expandFunc(String db_include_exp) {
String db_start_fld_Datefunc = " CONVERT(varchar(100), db_start_fld, 23)";
String db_end_fld_Datefunc = " CONVERT(varchar(100), db_end_fld, 23)";
return db_include_exp.replaceAll("db_start_fld",
db_start_fld_Datefunc).replaceAll("db_end_fld",
db_end_fld_Datefunc);
}
};
List<String> timeExpList = new ArrayList<String>() {
{
add(expandFunc(db_include_exp));
add(expandFunc(db_outclude_exp));
add(expandFunc(db_leftinclude_exp));
add(expandFunc(db_ritinclude_exp));
}
private String expandFunc(String db_include_exp) {
String db_start_fld_Timefunc = " CONVERT(varchar(100), db_start_fld, 8)";
String db_end_fld_Timefunc = " CONVERT(varchar(100), db_end_fld, 8)";
return db_include_exp.replaceAll("db_start_fld",
db_start_fld_Timefunc).replaceAll("db_end_fld",
db_end_fld_Timefunc);
}
};
List<String> finalList= new ArrayList<String>() {{
for (String dateExp : dateExpList) {
for (String timeExp : timeExpList) {
this.add(dateExp+" and "+timeExp.replaceAll("db_start_fld", db_start_fld).replaceAll("db_end_fld", db_end_fld));
}
}
}};
String sql=new ArrayList(){
private String exec( ) {
String exp_final=" 1=1 ";
for (String exp : finalList) {
//if(exp_final.length()==0)
exp_final=exp_final + " or ( "+exp +" ) ";
}
return exp_final;
}}.exec( );
System.out.println(sql);
}
4. 最终生成的sql
SELECT *
FROM tab
WHERE 1=1
OR (CONVERT(varchar(100), db_start_fld, 23)>=ui_start
AND CONVERT(varchar(100), db_end_fld, 23)<=ui_end
AND CONVERT(varchar(100), start_time, 8)>=ui_start
AND CONVERT(varchar(100), end_time, 8)<=ui_end)
OR (CONVERT(varchar(100), db_start_fld, 23)>=ui_start
AND CONVERT(varchar(100), db_end_fld, 23)<=ui_end
AND CONVERT(varchar(100), start_time, 8)<=ui_start
AND CONVERT(varchar(100), end_time, 8)>=ui_end)
OR (CONVERT(varchar(100), db_start_fld, 23)>=ui_start
AND CONVERT(varchar(100), db_end_fld, 23)<=ui_end
AND CONVERT(varchar(100), end_time, 8)>=ui_start
AND CONVERT(varchar(100), end_time, 8) <=ui_end)
OR (CONVERT(varchar(100), db_start_fld, 23)>=ui_start
AND CONVERT(varchar(100), db_end_fld, 23)<=ui_end
AND CONVERT(varchar(100), start_time, 8)>=ui_start
AND CONVERT(varchar(100), end_time, 8)<=ui_end)
OR (CONVERT(varchar(100), db_start_fld, 23)<=ui_start
AND CONVERT(varchar(100), db_end_fld, 23)>=ui_end
AND CONVERT(varchar(100), start_time, 8)>=ui_start
AND CONVERT(varchar(100), end_time, 8)<=ui_end)
OR (CONVERT(varchar(100), db_start_fld, 23)<=ui_start
AND CONVERT(varchar(100), db_end_fld, 23)>=ui_end
AND CONVERT(varchar(100), start_time, 8)<=ui_start
AND CONVERT(varchar(100), end_time, 8)>=ui_end)
OR (CONVERT(varchar(100), db_start_fld, 23)<=ui_start
AND CONVERT(varchar(100), db_end_fld, 23)>=ui_end
AND CONVERT(varchar(100), end_time, 8)>=ui_start
AND CONVERT(varchar(100), end_time, 8) <=ui_end)
OR (CONVERT(varchar(100), db_start_fld, 23)<=ui_start
AND CONVERT(varchar(100), db_end_fld, 23)>=ui_end
AND CONVERT(varchar(100), start_time, 8)>=ui_start
AND CONVERT(varchar(100), end_time, 8)<=ui_end)
OR (CONVERT(varchar(100), db_end_fld, 23)>=ui_start
AND CONVERT(varchar(100), db_end_fld, 23) <=ui_end
AND CONVERT(varchar(100), start_time, 8)>=ui_start
AND CONVERT(varchar(100), end_time, 8)<=ui_end)
OR (CONVERT(varchar(100), db_end_fld, 23)>=ui_start
AND CONVERT(varchar(100), db_end_fld, 23) <=ui_end
AND CONVERT(varchar(100), start_time, 8)<=ui_start
AND CONVERT(varchar(100), end_time, 8)>=ui_end)
OR (CONVERT(varchar(100), db_end_fld, 23)>=ui_start
AND CONVERT(varchar(100), db_end_fld, 23) <=ui_end
AND CONVERT(varchar(100), end_time, 8)>=ui_start
AND CONVERT(varchar(100), end_time, 8) <=ui_end)
OR (CONVERT(varchar(100), db_end_fld, 23)>=ui_start
AND CONVERT(varchar(100), db_end_fld, 23) <=ui_end
AND CONVERT(varchar(100), start_time, 8)>=ui_start
AND CONVERT(varchar(100), end_time, 8)<=ui_end)
OR (CONVERT(varchar(100), db_start_fld, 23)>=ui_start
AND CONVERT(varchar(100), db_end_fld, 23)<=ui_end
AND CONVERT(varchar(100), start_time, 8)>=ui_start
AND CONVERT(varchar(100), end_time, 8)<=ui_end)
OR (CONVERT(varchar(100), db_start_fld, 23)>=ui_start
AND CONVERT(varchar(100), db_end_fld, 23)<=ui_end
AND CONVERT(varchar(100), start_time, 8)<=ui_start
AND CONVERT(varchar(100), end_time, 8)>=ui_end)
OR (CONVERT(varchar(100), db_start_fld, 23)>=ui_start
AND CONVERT(varchar(100), db_end_fld, 23)<=ui_end
AND CONVERT(varchar(100), end_time, 8)>=ui_start
AND CONVERT(varchar(100), end_time, 8) <=ui_end)
OR (CONVERT(varchar(100), db_start_fld, 23)>=ui_start
AND CONVERT(varchar(100), db_end_fld, 23)<=ui_end
AND CONVERT(varchar(100), start_time, 8)>=ui_start
AND CONVERT(varchar(100), end_time, 8)<=ui_end)
5. 参考
java 时间段重合时间差 - 天才少年程序员-李荣盛专栏 - 博客频道 - CSDN.NET
JAVA中如何判断两个时间段是否有交集-CSDN论坛-CSDN.NET-中国最大的IT技术社区
比较两个日期间隔是否有碰撞的工具类，判断两个时间区间是否有交集（单位天） Java - 和申的日志 - 网易博客