query help - how to avoid duplicates?

[pouncer]

$sql_ = mysql_query("SELECT * FROM category_table WHERE `group` <> ''");

while ($row = mysql_fetch_array($sql_)) {

$group = $row['group'];

echo $group;

}

 

how can i make it stop showing duplicates because some categories belong to the same group.

[per1os]

"SELECT group FROM category_table WHERE `group` <> '' GROUP BY group"

or

"SELECT distinct(group) FROM category_table WHERE `group` <> '' GROUP BY group"

 

That should do the trick.

[neoform]

you need to have a key field to do this, but you can use something like this: (if the table has a key field called "id")

 

SELECT DISTINCT id FROM category_table WHERE `group` <> ''