在freeswitch中，查询坐席的时候，当place_call_ringall_callback返回0 则继续下一条的回调，当返回1则停止回调

#include <iostream>
using namespace std;
#include <sqlite3.h>
int callback(void*,int,char**,char**);
int main()
{
    sqlite3* db;
    int nResult = sqlite3_open("/usr/local/freeswitch/db/fifo.db",&db);
    if (nResult != SQLITE_OK)
    {
        cout<<"打开数据库失败："<<sqlite3_errmsg(db)<<endl;
        return 0;
    }
    else
    {
        cout<<"数据库打开成功"<<endl;
    }

    char* errmsg;
    string strSql;
    strSql = "select uuid, fifo_name, originate_string, simo_count, use_count, timeout, lag, next_avail, expires, static, outbound_call_count, outbound_fail_count, hostname from fifo_outbound";
    nResult = sqlite3_exec(db,strSql.c_str(),callback,NULL,&errmsg);
      if (nResult != SQLITE_OK)
    {
        sqlite3_close(db);
        cout<<errmsg<<endl;
        sqlite3_free(errmsg);
        return 0;
    }

    sqlite3_close(db);
    return 0;
}

int callback(void* ,int nCount,char** pValue,char** pName)
{
    cout<<"call once!!!!!1"<<endl;
    return 1;
}