I am quoting apex documentation:

Example 1

In addition, the sObject field key can be used with insert, update, or upsert to resolve foreign keys by external ID. For example:

  Account refAcct = new Account(externalId__c = '12345');

  Contact c = new Contact(account = refAcct, lastName = 'Kay');

Example 2

For example, suppose that custom object C1 has a foreign key c2__c that links to a child custom object C2. You want to create a C1 object and have it associated with a C2 record named 'xxx' (assigned to the value c2__r). You do not need the ID of the 'xxx' record, as it is populated through the relationship of parent to child. For example:

insert new C1__c(name = 'x', c2__r = new C2__c(name = 'xxx')); 

Now i have used this method a couple of times for different object relationship but the only one that i have not gotten to work is with Who or What relationships. Example:

insert new Task(name = 'test', subject = 'test', What = new Account(extid__c = 'test'));

Has anyone ever gotten this to work?

So what I am trying to accomplish is to upsert  List<sObject> with a field specification of what the external Id is. However this is the error message I get back when I try to save the class.

List<sObject> newlist = new List<sObject>();

upsert newlist ext_Id__c; (Error Msg: "Upsert with a field specification requires a concrete sObject type)

Any idea of a way around this?

So what I am trying to accomplish is to upsert  List<sObject> with a field specification of what the external Id is. However this is the error message I get back when I try to save the class.

List<sObject> newlist = new List<sObject>();

upsert newlist ext_Id__c; (Error Msg: "Upsert with a field specification requires a concrete sObject type)

Any idea of a way around this?

I am quoting apex documentation:

Example 1

In addition, the sObject field key can be used with insert, update, or upsert to resolve foreign keys by external ID. For example:

  Account refAcct = new Account(externalId__c = '12345');

  Contact c = new Contact(account = refAcct, lastName = 'Kay');

Example 2

For example, suppose that custom object C1 has a foreign key c2__c that links to a child custom object C2. You want to create a C1 object and have it associated with a C2 record named 'xxx' (assigned to the value c2__r). You do not need the ID of the 'xxx' record, as it is populated through the relationship of parent to child. For example:

insert new C1__c(name = 'x', c2__r = new C2__c(name = 'xxx')); 

Now i have used this method a couple of times for different object relationship but the only one that i have not gotten to work is with Who or What relationships. Example:

insert new Task(name = 'test', subject = 'test', What = new Account(extid__c = 'test'));

Has anyone ever gotten this to work?

I would like certain fields in our sfdc-environnement only to be filled with data in capital letters. So from the moment users input data that is not in capitals, they should get an error message when trying to save the record.

Is this possible?

 Thanks in advance!

So what I am trying to accomplish is to upsert  List<sObject> with a field specification of what the external Id is. However this is the error message I get back when I try to save the class.

List<sObject> newlist = new List<sObject>();

upsert newlist ext_Id__c; (Error Msg: "Upsert with a field specification requires a concrete sObject type)

Any idea of a way around this?