+Examples:+
Method:/qna /create
Parameters: 
\{
 "attrs":
\[
 "question":xxx,
 "answer":yyy,
 "user.id":userid
\]
\}
Response: 
\{
 "error":0,
"result":\{"id":1\}
\}
\\

Method:/qna/get
Parameters: 
\{
 "match":
\[
 \["id", "=", 2\],
\],
 "return":\["question", "answer"\],
\}
Response: 
\{
 "error":0,
"result":
\{
 "question":"xxx",
 "answer":"yyy",
\}
\}

Method:/qna/search
Parameters: 
\{
 "match":
\[
 \["user.id", "=", 2\],
\],
 "return":\["question", "answer"\],
\}
Response: 
\{
 "error":0,
"result":
\{
total:2,
rows:
\[
  \{
"question":"xxx",
  "answer":"yyy",
\},
  \{
"question":"xxx",
  "answer":"yyy",
\}
\]
\}
\}
\\