关于C语言编程实现数据的查询计算及插入的问题

[和过去说再见]

实习的时候有这样一个任务，就是有一个数据库存放的是列车的路程、速度、时间、经纬度等数据，这些数据理论上是需要每5秒以内传送一次的，但是有时可能会超过5秒，那么问题来了，如果两条数据超过5s，就根据已经有的数据（如相邻的两个数据）进行计算，再插入到数据库中，这样两个数据之间就小于5s了，不过有个问题就是，两个数据之间相差20的话，比如一个是10 然后是30，中间插15， 15到30之间就不插了，循环我也没循环明白，递归也不咋熟，纯小白一个，恳请各位大神帮帮忙。

这是我自己建的一个测试用数据库：
mysql> select * from test4;
+----+---------------------+-------+----------+
| id | time | speed | distance |
+----+---------------------+-------+----------+
| 1 | 2017-05-03 17:12:20 | 22 | 3847 |
| 2 | 2017-05-03 17:12:26 | 22 | 3847 |
| 3 | 2017-05-03 17:12:40 | 22 | 3847 |
+----+---------------------+-------+----------+


这是我的代码：

#include <mysql/mysql.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <stdlib.h>
long GetTick(char *str_time)
{
    struct tm stm;
    int iY, iM, iD, iH, iMin, iS;
 
    memset(&stm,0,sizeof(stm));
 
    iY = atoi(str_time);
    iM = atoi(str_time+5);
    iD = atoi(str_time+8);
    iH = atoi(str_time+11);
    iMin = atoi(str_time+14);
    iS = atoi(str_time+17);
 
    stm.tm_year=iY-1900;
    stm.tm_mon=iM-1;
    stm.tm_mday=iD;
    stm.tm_hour=iH;
    stm.tm_min=iMin;
    stm.tm_sec=iS;
 
    /*printf("%d-%0d-%0d %0d:%0d:%0d\n", iY, iM, iD, iH, iMin, iS);*/
 
    return mktime(&stm);
}
char* itstr(time_t value,char*a)
{
			
		   
                 struct tm t;
		    time_t result;
		    t.tm_year = 70;
		    t.tm_mon = 1;
		    t.tm_mday = 0;
		    t.tm_hour = -8;
		    t.tm_min = 0;
		    t.tm_sec = 0;
		    result = mktime(&t);
		    result += value;
		    memcpy(&t, localtime(&result), sizeof(struct tm));
		sprintf(a,"%d-%02d-%02d %02d:%02d:%02d", t.tm_year + 1900, t.tm_mon, t.tm_mday, t.tm_hour, t.tm_min, t.tm_sec);
		return a;
}
int main()
{
        MYSQL mysql;
        MYSQL_RES *res;
        MYSQL_ROW row;
        char query[512] = {0};
        int flag, t;
	 char sql[512] = {0};
	char *sql1;
        mysql_init(&mysql);
        if(!mysql_real_connect(&mysql, "localhost", "root", "yang5716", "test", 3306, NULL, 0)) {
                printf("Failed to connect to Mysql!\n");fprintf(stderr,"Failedtoconnecttodatabase:Error:%s\n",mysql_error(&mysql));             return 0;
        }else {
                printf("Connected to Mysql successfully!\n");
        }
	
		sprintf(query,"SELECT time,speed,distance from test4;");
	
	
        /*查询，成功则返回0*/
        flag = mysql_real_query(&mysql, query, (unsigned int)strlen(query));
        if(flag) {
                printf("Query failed!\n");
                return 0;
        }else {
                printf("[%s] made...\n", query);
        }

	long savetime,savespeed,savedistance=0;
        /*mysql_store_result讲全部的查询结果读取到客户端*/
        res = mysql_store_result(&mysql);
        /*mysql_fetch_row检索结果集的下一行*/
        while(row = mysql_fetch_row(res)) {
			
              
                    if(savetime&&savespeed&&savedistance)
			{	
				  
				
				while(GetTick(row[0])-savetime>5)
				  {
					char a[256]={0};
					time_t time1=savetime;
					time_t time2=GetTick(row[0]);
					int speed1=savespeed,speed2=atoi(row[1]);	
					int distance=savedistance;
					int fspeed,fdistance=0;
					time_t ftime;
					ftime = time1 + 5;
					fspeed = (speed1+speed2)/2;
					fdistance =5 * fspeed+distance;
					printf("time1 %d time2 %d  speed1 %d\n",time1,GetTick(row[0]),speed1);
				//printf("%d %d %d\n",ftime,fspeed,fdistance);
				printf("%s\n",itstr(ftime,a));
				sprintf(sql,"insert into test4(time,speed,distance) values('%s',%d,%d);",itstr(ftime,a),fspeed,fdistance);
				printf("%s\n",sql);
				
				flag = mysql_real_query(&mysql, sql, (unsigned int)strlen(sql));	
					savetime=GetTick(row[0]);savespeed=atoi(row[1]);savedistance=atoi(row[2]);
					
					
				 	
				}	
			 }
			else			
			savetime=GetTick(row[0]);savespeed=atoi(row[1]);savedistance=atoi(row[2]);
							
						
              
			
                
        }
        mysql_close(&mysql);
        return 0;
}

执行之后这样：
+----+---------------------+-------+----------+
| id | time | speed | distance |
+----+---------------------+-------+----------+
| 1 | 2017-05-03 17:12:20 | 22 | 3847 |
| 2 | 2017-05-03 17:12:26 | 22 | 3847 |
| 3 | 2017-05-03 17:12:40 | 22 | 3847 |
| 14 | 2017-05-02 17:12:25 | 22 | 3957 |
| 15 | 2017-05-02 17:12:31 | 22 | 3957 |
+----+---------------------+-------+----------+
5 rows in set (0.00 sec)