从Web服务和mysql查询多个数据的最佳方法？

Question

I have an android app which uses java rest api, which gets the data from mysql database.

After I open the app, I download a list of some items. Then, I make another 5 requests to rest api to get other connected resources, so:

First I download a list of shops. Then, having these shops ids, I make 5 http requests to rest api and it fetches (from mysql) lists of photos (not actual images, just urls and ids), ratings, opening hours and 2 more things

This makes 6 api (and db) calls and it takes a long time. Is there a better way to do it?

Answer 1

You might rewrite the multiple queries into a single JOIN and fetch them in a single network round trip.

Be sure you understand where the time is being spent and why. Your queries might be slow if you have WHERE clauses that don't use indexes. Run EXPLAIN PLAN and see if there's a TABLE SCAN being executed. If you see one, you can immediately improve performance by adding appropriate indexes on the columns in the WHERE clauses.

Answer 2

Why don't yout retrieve all those data in the first call? the response of restapi can be json or xml.

REQUEST: GET /shop/list

RESPONSE XML:
<shops>
  <shop name="shop1" img="../../img1.jpg" ></shop>
  <shop name="shop2" img="../../img2.jpg" ></shop>
  <shop name="shop3" img="../../img3.jpg" ></shop>
</shops>

RESPONSE JSON:
[{name:"shop1",img:"../../img1.jpg"},
{name:"shop2",img:"../../img2.jpg"},
{name:"shop3",img:"../../img3.jpg"}]

You could handle these responses in your Java/Android application