Recieving error "Unexpected token '<'." while defining a list in anon apex

Question

The following code returns the error:

List<ContentDocumentLink> docLinks = [SELECT ContentDocumentId FROM ContentDocumentLink where LinkedEntityId in ( SELECT Id FROM Case ) and LinkedEntity.Type='Case'];

Set<String> docIds = new Set<String>();

for(ContentDocumentLink cdl : docLinks){
    docIds.add(cdl.ContentDocumentId);
}

List<ContentDocument> docsToDelete = [SELECT Id FROM ContentDocument WHERE Id IN docIds];
system.debug(docsToDelete.size());

And this is the exact error:

I don't see why this should be happening and I suspect it may be a bug. Does anyone know what causes this?

Answer 1

Running this through my own execute anonymous window, I was able to reproduce the issue.

Turns out that the problem is indeed the missing colon : in your query.

When using a variable in a query (typically called a bind, or binding, see relevant documentation), we need to use : to let Salesforce know that it is a variable.

So the correct query would be List<ContentDocument> docsToDelete = [SELECT Id FROM ContentDocument WHERE Id IN :docIds];

As for why this generates that particular error, I'm not sure. Best guess would be that some combination of how anonymous apex sends code to Salesforce, and the lexer Salesforce is using causes some tokenization issues earlier in the line.