You are here:
ApexGuru Antipattern: Redundant SOQL
Executing multiple SOQL queries on the same sObject with identical or nearly identical filter conditions creates inefficiencies. This practice wastes governor limits and increases transaction time because it requires more database round-trips. Processing separate query responses wastes CPU time and heap space.
Scope
Detection and recommendation
Detection Example
//Apex
// Bad: Two round-trips to the database
User userA = [SELECT Id FROM User WHERE ContactId = :idA];
User userB = [SELECT Id FROM User WHERE ContactId = :idB];
Recommendation
Merge these queries into fewer SOQL statements, followed by in-memory filtering in Apex. Query all records at the same time and map them for easy access. This scales regardless of whether you need 2 records or 200.
//Apex
// Good: One round-trip using a Set and Map
Set<Id> contactIds = new Set<Id>{ idA, idB };
// 1. Bulk Query
List<User> users = [SELECT Id, ContactId FROM User WHERE ContactId IN :contactIds];
// 2. In-Memory Organization (The Map Pattern)
Map<Id, User> userMap = new Map<Id, User>();
for(User u : users) {
userMap.put(u.ContactId, u);
}
// 3. Retrieve efficiently
User userA = userMap.get(idA);
User userB = userMap.get(idB);
この記事で問題は解決されましたか?
ご意見をお待ちしております。
