Comments on: List has no rows for assignment to SObject

By: Jorma Soucey

Jorma Soucey — Fri, 09 Oct 2009 18:36:23 +0000

Whenever possible, it’s best to try to fit a query that could return nothing inside a try–>catch pair:

Player__c[] players = new Player__c[]();
try{
players = [SELECT Id from Player__c where Name = :username];}
catch {system.queryexception players){
return;
}

This avoids both the runtime error and the null reference.

By: Richard Vanhook

Richard Vanhook — Fri, 09 Oct 2009 17:10:25 +0000

My safeguard around this issue is to just wrap a try/catch – so line 2 above would become:

Contact c1 = null;
try{
c1=[SELECT Id FROM Contact LIMIT 1];
}catch(QueryException e){}
if(c1 != null){
//do something
} else {
//or gracefully handle no contact found
}

By: Wes

Wes — Fri, 09 Oct 2009 13:53:59 +0000

I’ve debated with myself how to handle this sort of thing before, I blogged about it some time ago but I prefer to use a single var and surround it with a try-catch (http://developinthecloud.wordpress.com/2009/07/09/handling-system-queryexception/). Of course your method and a try-catch are simply the same thing implemented differently:) Good article.

By: Scott Hemmeter

Scott Hemmeter — Mon, 14 Sep 2009 15:29:15 +0000

An approach I often use is to always use a FOR loop for the query. It will only go into the loop if something is returned. Only downside is that you need to declare variables outside the loop you want to use them outside the loop. If you declare them in th loop, the system can’t see them after the loop is complete.

By: The Enforcer

The Enforcer — Sun, 13 Sep 2009 02:38:54 +0000

Oops! Thanks for finding the error, Tom! I was checking players != null, but should be checking players.size() > 0. Now corrected.

By: Tom Davies

Tom Davies — Sat, 12 Sep 2009 23:45:54 +0000

IMHO it is nocer to get an immediate runtime exception than a null reference which might blow up later.

Is the last example really correct? That is, does SELECT return null for no rows rather than an empty list?