sqlite3.6.17 怎么向字符串里插入整型变量

#include<stdio.h>
#include<stdlib.h>
#include<sqlite3.h>

int main()
{
 sqlite3 *db=NULL;
 char *zErrMssg=0;
 int i=1;
 sqlite3_open("liu.db",&db);
 char *sql="create table student(id ,name,age);";
 sqlite3_exec(db,sql,0,0,&zErrMssg);
 sql="insert into student values(i,'zhang',18);";
 sqlite3_exec(db,sql,0,0,&zErrMssg);
 return 0;
}

不着哪里错了啊 大家帮帮忙啊"+i+"没用啊

sql="insert into student values(i,'zhang',18);";

i不是这么放进去的。。。用sprintf格式化sql="insert into student values(%d,'zhang',18);";