Argthtjtr

how to write a trigger on account object(salesfroce) if the existing record then update some fields according to you else create a new Records ?

Thanks

How about using upsert? It allows you to either insert record or update if it already exists. insert and update in a single, smart command.
You want to update record, and if it does not exist, create new one.
With upsert you can first try to obtain record (if nothing found, create new instance), then set your fields up, and finally, upsert it.

Like:

Account myAcc;

try {

    myAcc = [ SELECT Id, Name FROM Account where Id='someIdImLookingFor'];

    myAcc.Name = 'My desired name';

catch (Exception e) {

    myAcc = new Account(Name='My desired name');

}

upsert myAcc

'Upsert' is the best way to do that. If the record is present it helps you to update the record else create a new one.

Account acctsList = [SELECT Id, Name, BillingCity FROM Account WHERE BillingCity = 'Bombay'];

 for (Account a : acctsList) {

    a.BillingCity = 'Mumbai';

}

Account newAcct = new Account(Name = 'Acme', BillingCity = 'San Francisco');

  acctsList.add(newAcct);

try {

   upsert acctsList;

} catch (DmlException e) {

  // Process exception here

}