help in Apex trigger

Question

I have requirement to update user record based on insert/update Junction object between custom object and user. I need to update user custom field accountdef with junction object values(more than one for given user).I am newbie to Apex coding and having trouble with bulkifying the code. I have started something like this but could not navigate list to update user record.Any help will be appreciated.

trigger UpdateUserGUL on GUL_Account_to_User_Junction__c (after insert) {


    set<id> UserList    = new Set<id>();

    for (GUL_Account_to_User_Junction__c junc : Trigger.New){

       //add set of Ids
        userList.add(junc.UserId__c);

    }
   //query junction records based on userid set

GUL_Account_to_User_Junction__c[] juncrecords = [select id,UserId__c,GUL_Account_Name__c,Chatter_Group_Name__c 
                                                     from GUL_Account_to_User_Junction__c where UserId__c IN :UserList];
     Map<id, String> AccountsMap = new Map<id, String>();
     Map<id, String> ChatterMap = new Map<id, String>();


    //Create Map of records 
    for (GUL_Account_to_User_Junction__c j : juncrecords) {
    AccountsMap.put(j.UserId__c, j.GUL_Account_Name__c);
        ChatterMap.put(j.UserId__c, j.Chatter_Group_Name__c);

  }

Answer 1

Edit: per Adrian's comment you technically don't need to query the User record. You can use the User Id from the junction object alone to update the records.

List<User> userList = new List<User>();

for(GUL_Account_to_User_Junction__c junction : Trigger.new) {
    User userRecord = new User();
    userRecord.Id = junction.UserId__c;
    userRecord.Field_To_Update__c = ???;
    userList.add(userRecord);
}
update userList;

---

Original Answer

If you need to update the User object then you need to query the User records.

Map<Id, User> userMap = new Map<Id, User>([SELECT Id, Field_To_Update__c FROM User WHERE Id IN :userList];

Then loop through your junction object and update the User records per your requirements.

for(GUL_Account_to_User_Junction__c junction : Trigger.new) {
    User userRecord = userMap.get(junction.UserId__c);
    userRecord.Field_To_Update__c = ???;
}
update userMap.values();