Hello all,

First post here, I am trying to learn Apex and a newbie at this. I am trying to do the following trailhead:

https://trailhead.salesforce.com/trails/force_com_dev_beginner/modules/apex_triggers/units/apex_triggers_intro

In the example, they provide the following code:

// Get the related opportunities for the accounts in this trigger Map<Id,Account> acctsWithOpps = new Map<Id,Account>( [SELECT Id,(SELECT Id FROM Opportunities) FROM Account WHERE Id IN :Trigger.New]);

I don't understand why map is declared of type Account but then the subquery (SELECT Id FROM Opportunities) returns IDs of type opportunities?

Second question:

System.debug('acctsWithOpps.get(a.Id).Opportunities.size()=' + acctsWithOpps.get(a.Id).Opportunities.size());

Since opportunities is a child object to account, why do we use get(a.id).opportunities because I thought the dot notation was to traverse from child to parent?

Appreciate all the help...
J




 

Hello all,

First post here, I am trying to learn Apex and a newbie at this. I am trying to do the following trailhead:

https://trailhead.salesforce.com/trails/force_com_dev_beginner/modules/apex_triggers/units/apex_triggers_intro

In the example, they provide the following code:

// Get the related opportunities for the accounts in this trigger Map<Id,Account> acctsWithOpps = new Map<Id,Account>( [SELECT Id,(SELECT Id FROM Opportunities) FROM Account WHERE Id IN :Trigger.New]);

I don't understand why map is declared of type Account but then the subquery (SELECT Id FROM Opportunities) returns IDs of type opportunities?

Second question:

System.debug('acctsWithOpps.get(a.Id).Opportunities.size()=' + acctsWithOpps.get(a.Id).Opportunities.size());

Since opportunities is a child object to account, why do we use get(a.id).opportunities because I thought the dot notation was to traverse from child to parent?

Appreciate all the help...
J