Checking for an empty query result

Scope: managed applications, mobile applications, and ordinary applications.

1. If you need to check whether a query result is empty, employ the IsEmpty method. Otherwise, it will take time to fetch the data and save the result-set.

Incorrect:

Selection = Query.Execute().Select();
If Selection.Next() Then
  Return TRUE;
Else
  Return FALSE;
EndIf;

Correct:

Return NOT Query.Execute().IsEmpty()

Best practices

2. Do not embed IsEmpty when you need to fetch or import the query result.
Incorrect:

QueryResult = Query.Execute();
If NOT QueryResult.IsEmpty() Then // unnecessary call
  Selection = QueryResult.Select(); 
  While Selection.Next() Do
  ...

Correct:

Selection = Query.Execute().Select();
While Selection.Next() Do
...