Hi all,

I am newbie to apex Batch classes. I need to understand how Apex batches execute(the process).

I know how to write apex classes and trigeers. but totally confused in following Apex batch code. Kindly give me some tips/knowledge/information on how easily I can write apex batches.

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1. global class Beautification's implements Database.Batchable<sObject>{
2. global final String Query;
3. global final String Entity;
4. global final String Field;
5. global final String Value;
6. global UpdateAccountFields(String q, String e, String f, String v){
7. Query=q; Entity=e; Field=f;Value=v;
8. }
9. global Database.QueryLocator start(Database.BatchableContext BC){
10. return Database.getQueryLocator(query);
11. }
12. global void execute(Database.BatchableContext BC,
13. List<sObject> scope){
14. for(Sobject s : scope){s.put(Field,Value);
15. } update scope;
16. }
17. global void finish(Database.BatchableContext BC){
18. }
19. }

The following code can be used to call the above class:

1. Id batchInstanceId = Database.executeBatch(new UpdateInvoiceFields(q,e,f,v), 5);

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I am little confused of the following lines:

1. ""query","entity","field","value"" declared as variable and at 7th line why it is assigned to q,e,f,v.

2.  return Database.getQueryLocator(query)...?

3.  [List<sObject> scope)  {  for(Sobject s : scope){s.put(Field,Value);]..in line 13,14.

Can't we use directly Account,lead,contact or any custom object. Like this:[ List<account>scope { for(account a:scope...].

4. Id batchInstanceId = Database.executeBatch(new UpdateInvoiceFields(q,e,f,v), 5);

can please explain line by line.

thank you in advance.

any kind of explanation/suggestions/information is highly appriciated.