Salesforce Trigger Best Practices

System.LimitException: Too many SOQL queries: 101

Triggers are executed before or after records of a particular type are inserted, updated, or deleted from the Force.com platform database.

Before writing a trigger a requirement must be clear on which type of operation a trigger needs to run.

The following are the best practices with Example:

·  Minimizing  the number of data manipulation language (DML) operations by adding records to collections and performing DML operations against these collections.

·  Minimizing the number of SOQL statements by preprocessing records and generating sets, which can be placed in single SOQL statement used with the IN clause

Use of List ,Set and Maps helps avoiding governer Limit Exceptions.

The below code is not considered as a good code as it will eventually hit governor limits.

for (Account a : trigger.new) { for (Contact c : [select id,otherphone from contact where accountid = :a.id]) { c.OtherPhone= a.Phone; update c;

Good practice using List,Maps and Sets.

Set<ID> ids = Trigger.newMap.keySet(); List<Account> Acc=[select id,otherphone from Account where id in :ids]; List<Contact> c=[select id,otherphone from contact where Accountid IN : Acc]; Map<id,Account> ContactMaps=new Map<Id,Account>(); List<contact>Updatecontact=new List<Contact>(); for(Account:Acc) { ContactMaps.put(Acc.id,Acc); } for(Contact con:c) { Con.OtherPhone=contactMaps.get(con.Accountid).phone; Updatecontact.add(Con); } Update Updatecontact;