the_content() from calendar date, the_excerp() from category/archive

Hi,

After not finding this topic in the first 5 pages in the plugin and hacks category, I decided to write an own entry.

I’m trying to display a blog entry in full with the_content() function when it was clicked on a calendar date and it would only show that respective blog entry. And when clicked on a category or on a month in the archive, it would show a list of excerps (using the_excerp() function).

I’m struggeling with the right if … then… else criteria.

Using the following if command:
<?php if (have_posts()==1):?>
to clarify if there’s only one blog entry matching the criteria, and then to display it in full (otherwise excerps), results in an infinite loop, the same excerp is listes infinitely.

Using it this way:
<?php if (have_posts()==the_post()):?>
results in the second entry of an excerp list being displayed in full, all the others being excerps.

I guess this has been solved earlier, just couldn’t find the working solution yet. And since I’m not very professional in my coding skills, it might be easy to solve.
Anyone has some ideas?
Thanks in advance.