NSString*sqlStr=@"insert into chatinfo(msg_fromId,msg_toId,session_id,msg_id,version,send_time,msg_seq,msg_scope,msg_type,msg,dur,name,md5,url,thumb_url,cover_url,ext,w,h,size,isSentSuccess,bymyself,isRead,tid) values (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)";
NSString*sql=[NSStringstringWithFormat:@"SELECT * FROM chatinfo where (msg_fromId =? and msg_toId = ?) or (msg_fromId =? and msg_toId = ?) order by send_time desc limit ?,?"];