Multiple Same Values displayed

Try to modify views_query.inc. In line 654, change "SELECT $fields..." into "SELECT DISTINCT $fields...". This should work in table view. I'm not quite sure if this patch produces some side-effects, but I think "SELECT DISTINCT" is the natural expected behaviour.

Performing a mass closing of all issues over 180 days old. Please reopen if needed.

This is a still a problem and I have need to sort out a solution too.
Trying to show a list of Artists on a store where I am selling thousands of records. I just want to display a distinct list of the artists and then link them to go to another view showing their records. When using views, it will print out the same artists name multiple times, if I have, for example, 10 records by the same person.

I have implemented a custom module that, for now will solve the issue for myself.
It probably is a bad way of doing things, as I am a beginner at Drupal.
I have used hook_views_pre_render to catch the fields before they are printed out and qiuckly removed all duplicate values in the easiest way I could using a simple for loop.
This code requires that you have your fields sorted alphabetically and are only displaying one field. (thats how I differentiated it from my other views)

function distinctviews_views_pre_render(&$view) {
	//get the objects returned, and see if it is a one field view
	if(count($view->display['default']->display_options['fields'])== 1){
		//loop through the fields and check if results are identical. (This assumes the values are sorted alphabetically)
		for($loopcount=0; $loopcount+1 < count($view->result); ++$loopcount){
//to look in a different field, just change node-data_field_artist_field_artist_value to the field you want
			if($view->result[$loopcount]->node_data_field_artist_field_artist_value == $view->result[$loopcount+1]->node_data_field_artist_field_artist_value){
				//remove entry from array
				unset($view->result[$loopcount+1]);
				//go back and check the same record because we just removed one
				--$loopcount;
			}
		}
	}
}

Since writing the above code, I changed it slightly and have been playing about with hook_views_query_alter.
Unfortunately, I can't figure out how to add the "GROUP BY" into the SQL using this hook - doing so will sort me out and give a clean solution to this problem.
Any ideas?

I have found out more after scouring the web! It seems this is a common problem.
http://groups.drupal.org/node/18277
The above discussion revealed that using hook_views_query_alter used to work.
Views 2.3 broke that, so I have raised this as an issue in the views forum.

I am currently living with Views 2.2 until I know the problem is resolved.
My issue is here
http://drupal.org/node/624646

After being told the views problem is by design, I hacked the problem myself after playing around in query.inc
In the current views version, (2.7, drupal 6) on line 984, I replaced the line

$groupby = "GROUP BY " . implode(', ', array_unique(array_merge($this->groupby, $non_aggregates))) . "\n";

with

$groupby = "GROUP BY " . implode(', ', array_unique($this->groupby)) . "\n";

Which allowed me to create a custom module that used hook_views_query_alter to add my group by clause without any problems! I think it goes against some things, but it works for my website, which is what I was looking for!

For anyone with this problem, here is my custom module code - my module is called distinctviews.

The code from distinctviews.module is here

//declare views support
function distinctviews_views_api() {
   return array(
    'api' => 2,
	'path' => drupal_get_path('module', 'distinctviews')
  );
}

function distinctviews_views_query_alter($view, $query) {
  // example code here
  	
	//Only alter the output if we are retrieveing 4 or less fields - this is my way of only grouping the views with one term in them
	if(count($query->fields) == 4 || count($query->fields) == 3){
		
		/*to add the groupby, we insert the name of the field into '$query->groupby[]'.
		* to get the name of the field, I have taken the orderby field and removed the ASC from the end.
		* if you are using your view for one term in total on your website, then you could replace 'str_replace(" ASC", "", $query->orderby[0]);'
		* with just the name of the field.
		* For views > v2.3  you will also need to alter query.inc please see my post here http://drupal.org/node/240872#comment-2235716 to do this.
		*/
  		$query->groupby[] = str_replace(" ASC", "", $query->orderby[0]);
	}
	
	
	return $query;
}

I think you don't have to modify you can just use arguments.

See #2 at http://drupal.org/node/478696

(originally mine, didn't see this OP - sorry for the duplicate!)