Does SOQL query get consumed when querying from an empty set?

Question 1

Let’s say I have a following piece of code:

Set<Id> accountIds = new Set<Id>();

for(Contact c : [SELECT Name FROM Contact WHERE AccountId IN :accountIds]){
    System.debug(c);
}

The accountIds set is obviously empty in the example above, but will my Apex code consume 1 SOQL query?

Question 2

Yes, even though the Set<Id> accountIds is empty, 1 SOQL query will be executed and will be counted against the 100 SOQL queries limit.

On a similar note, the code below won’t be counted as 1 DML statement:

List<Account> accounts = new List<Account>();
update accounts;

Answer