{% cache %} tag creates duplicate entries

Question

When using the {% cache %} tag on an entry type, it caches the first entry on the page (multiple pages as well), and uses the cached entry for every other instance of that entry type on the page. What am I doing wrong? Here's an example. This one isn't complex so not sure it's worth caching, but I have some entries that have multiple relational fields.

{% for block in entry.contentMatrix %}
  {% if block.type == "copyOneCol" %}
    {% cache %}
        .... output entry type data
    {% endcache %}

  ...next if, etc.
{% endfor %}

Answer 1

Correct... by default the {% cache %} tag will use the current page's URI (including querystring) for the cache key. If you want to change that behavior you'll need to specify the using key parameter and supply a unique key. Although you might want to make something more unique than just block.id as that will be an integer and could potentially easily be overwritten.