How to know the mandatory fields in standard or custom objects?

In Apex you can check this by global describe :

Schema.DescribeSObjectResult r = User.sObjectType.getDescribe();
Map<String,Schema.SObjectField> M = r.fields.getMap();
for(String fieldName : M.keySet())
{ 
 Schema.SObjectField field = M.get(fieldName);
 Schema.DescribeFieldResult F = field.getDescribe();
 //A nillable field can have empty content. A isNillable Boolean non-nillable field must have a value for the object to be //created or saved. 
 // if F.isNillable() is false then field is mandatory
 Boolean isFieldreq = F.isNillable() ;
 System.debug ('F = ' + fieldName + ' isnul= ' + isFieldreq);
}

• This reply was modified 8 years, 7 months ago by  Ravi.