Multiple queries in the same view

Play Framework
1

Hello,

I would like to run multiple queries then show results in a page such as :
https://adminlte.io/themes/v3/index.html

I create a first controller query :

// Showing results as a EbeanList
  public CompletionStage<Result> index() {
    return SearchSomething().thenApplyAsync((List<LocationExtractedData> infos) -> {                   
          return ok(views.html.sitemap.index.render(  Sysuser.findByUserName(request().username()), infos)  );
            }, httpExecutionContext.current());
  }	
	
	
  public CompletionStage<List<LocationExtractedData>> SearchSomething() {
    return CompletableFuture.supplyAsync(() -> {
        
		return db.withConnection(
              connection -> {
				
				// Imagines this is a complexe QUERY (Later in the future...)
				final String sql =  "SELECT sysuser_id, role_id "
				                   +"from sysuser_role "
								   +"where sysuser_id = '1' "
								   +"and role_id in ('1','2','3','4','5') ";
				final RawSql rawSql = RawSqlBuilder.parse(sql).create();				
				Query<LocationExtractedData> query = Ebean.find(LocationExtractedData.class);  
                query.setRawSql(rawSql);
                List<LocationExtractedData> list = query.findList();  
				
				return list;				              				
              });
        
		}, httpExecutionContext.current());
  }

Can you telling me how to run multiple and optimized queries in the same time for my page full of dashboards, charts and tables!

If i create multiple list of ebeanLists ( queries ), does this will affect the loading of my page ?
IF not, then, what should i do ?

Thank you in advance,

2

Hi @placebo86,

you have two options:

  1. each of the dashboard query is mapped to a separate Play action so a single client sends multiple requests (one per widget in the dashboard) and starts painting each widget as soon as the response is delivered
  2. invoke multiple CompletableFuture.supplyAsync(() -> {return db.withConnection( ... (one per query) and compose the results using thenCombine's in the CompletableFuture's API.

The former has a nicer UX since users stat to see data as soon as it’s available but produces a lot of HTTP requests.
The later will not render any information until all views completed.

Cheers,

3

Thank you for your response,
What do you think about this which works good for me : Using play with existing database ( models )

However, i don’t know how to combine more than 2 completionstage, can you help please in my controller to send more list of data (EbeanList) to my view , thank you so much

4

Hi @placebo86,

I thiunk Baeldung does a great job at explaining exactly that so I won’t try to be half as good as them.

Cheers,