Given Account - MaintenancePlan relationship, I have this SOQL:
SELECT Id, (SELECT id from MaintenancePlans WHERE Id = 'xxxxxxxxpUGAS') FROM Account
Problem is that I just need to get the MaintenacePlans which Id is specified in query, but I get all Accounts of my ORG. So, I need to make a query that just get MaintenancePlan with the ID 'xxxxxxxxpUGAS'.