多进程插入mysql数据库
如何编译？
gcc -Wall -o a.out $(mysql_config --cflags) mysql_insert.c $(mysql_config --libs)

#include <stdio.h>  #include <stdlib.h>  #include <string.h>#include <sys/time.h>#include <unistd.h>#include <mysql/mysql.h>#include<sys/types.h>#include<sys/wait.h>#define DB_HOST "127.0.0.1"#define DB_USER "root"#define DB_PASS ""#define DB_NAME "test"#define DB_PORT 3307int main(int argc, char **argv){MYSQL mysql;unsigned int i;int rtn; /*子进程的返回数值*/unsigned int process_no;unsigned int userId;unsigned int type;unsigned int itemCate;unsigned int itemType;unsigned int itemNum;unsigned int totalCost;unsigned int consumeTime;unsigned int leftBalance;char itemName[1000] ;char sql[20000] ;    struct timeval time_start,time_end;    float execute_time;    //srand(time(0));for(process_no = 1; process_no < 18; process_no++){if(fork() == 0){    // 开始执行时间    gettimeofday(&time_start,NULL);mysql_init(&mysql);if(!mysql_real_connect(&mysql,DB_HOST,DB_USER,DB_PASS,DB_NAME,DB_PORT,NULL,0)){fprintf(stderr, "Failed to connect to database: Error: %s\n",mysql_error(&mysql));}mysql_query(&mysql,"SET NAMES utf8");for(i = 0; i < 444444; i++){sprintf(itemName,"%s","");userId = rand()%19071388 + 1;type = rand()%4 + 1;itemCate = rand()%15 + 1;itemType = rand()%100 + 1;itemNum = rand()%100 + 1;totalCost = rand()%10000 + 1;consumeTime = rand()%1309120853 + 1;leftBalance = rand()%10000 + 1;sprintf(sql,"insert into user_consume1(userId,type,itemCate,itemType,itemNum,totalCost,consumeTime,leftBalance,itemName)values(%d,%d,%d,%d,%d,%d,%d,%d,'')",userId,type,itemCate,itemType,itemNum,totalCost,consumeTime,leftBalance);if(mysql_query(&mysql,sql)){fprintf(stderr,"query failed:%s",mysql_error(&mysql));}}mysql_close(&mysql);// 结束执行时间gettimeofday(&time_end,NULL);execute_time = (time_end.tv_sec - time_start.tv_sec) + (time_end.tv_usec - time_start.tv_usec)/1000000;printf("execute time:%f\n",execute_time);exit(0);}else{/* 父进程， 等待子进程结束，并打印子进程的返回值 *///wait ( &rtn );//printf("child process return %d\n",rtn);//return 0;//printf("execute child process return %d\n",process_no);}}return 0;}