I have a custom object called Visitor with two custom fields, Name and Identifier. I am trying to add a record with this piece of controller code:

 public String getResponse() {
        System.debug('I am in!');

        if(validate()) {
            Visitor newVisitor = new Visitor();
            newVisitor.Name = 'John Smith';
            newVisitor.Identifier = 'john@somewhere.com';
            insert newVisitor;
            return '{"success":"true"}';
        }

        return '{"success":"false"}';
    }

When I try to save my code, I get this error:

Compile Error: Invalid type: Visitor at line 13 column 38

What am I doing wrong here?

Attribution to: JannieT

Possible Suggestion/Solution #1

Visitor should be Visitor__c. All custom objects are suffixed with __c, as should all of your custom fields on either standard or custom objects. So, your code would look something like this:

Visitor__c newVisitor = new Visitor__c ();
newVisitor.Name = 'John Smith';
newVisitor.Identifier__c = 'john@somewhere.com';
insert newVisitor;

Only standard fields are not suffixed with __c, e.g. Name, Id, CreatedDate etc.

EDIT: boots and braces with Try/Catch

See the docs for a full description of the Insert operation:

http://www.salesforce.com/us/developer/docs/apexcode/Content/apex_dml_insert.htm

Doing a DML insert/update/upsert could result in an exception depending on a number of factors:

• It could be that the operation will mean that you exceed a Governor limit (see
  http://www.salesforce.com/us/developer/docs/apexcode/Content/apex_gov_limits.htm). If you are inserting multiple records, 'bulkification' will most likely be required to prevent this.
• It could also (and more likely) be caused by an issue with the record that you are trying to insert (e.g. missing required field, failed validation etc.).

Surrounding your operation with a Try/Catch is always good practice and will allow you to fail gracefully should the worst happen. Note, you cannot fail gracefully with a Try/Catch for a Governor limit issue.

There are essentially two ways to Try/Catch for DML statements (sorry, formatting has gone screwy):

This will suffice for a single record (though you could use the second option here too):

try
{
    insert newVisitor;
}
catch( DmlException ex )
{
    // fail gracefully
}

This may be preferable for multiple records, where the 'false' parameter indicates that this is (not) an 'all or nothing' insert:

Database.SaveResult[] MySaveResult = Database.Insert(newVisitors, false);
for (Database.SaveResult sr : MySaveResult) {
    if (!sr.isSuccess()) {
        // Operation failed, so get all errors                
        for(Database.Error err : sr.getErrors()) {
            System.debug('The following error has occurred.');                    
            System.debug(err.getStatusCode() + ': ' + err.getMessage());
            System.debug('Fields that affected this error: ' + err.getFields());
        }
    }
}

Attribution to: Phil Hawthorn
This content is remixed from stackoverflow or stackexchange. Please visit https://salesforce.stackexchange.com/questions/4710