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Id
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CreationDate
2010-04-22T12:07:16.117
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2018-04-02T22:14:51.177
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2018-04-02T22:14:51.177
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2690521
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2
Score
55
ViewCount
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LastEditorDisplayName
text
Body
Use <a href="https://docs.djangoproject.com/en/1.11/ref/models/querysets/#count" rel="noreferrer"><code>count()</code></a>: <pre><code>sc=scorm.objects.filter(Header__id=qp.id) if sc.count() > 0: ... </code></pre> The advantage over e.g. <code>len()</code> is, that the QuerySet is not yet evaluated: <blockquote> <code>count()</code> performs a <code>SELECT COUNT(*)</code> behind the scenes, so you should always use <code>count()</code> rather than loading all of the record into Python objects and calling <code>len()</code> on the result. </blockquote> Having this in mind, <a href="https://docs.djangoproject.com/en/1.11/ref/models/querysets/#s-when-querysets-are-evaluated" rel="noreferrer">When QuerySets are evaluated</a> can be worth reading. <hr> If you use <code>get()</code>, e.g. <code>scorm.objects.get(pk=someid)</code>, and the object does not exists, an <code>ObjectDoesNotExist</code> exception is raised: <pre><code>from django.core.exceptions import ObjectDoesNotExist try: sc = scorm.objects.get(pk=someid) except ObjectDoesNotExist: print ... </code></pre> Update: it's also possible to use <a href="https://docs.djangoproject.com/en/1.11/ref/models/querysets/#exists" rel="noreferrer"><code>exists()</code></a>: <pre><code>if scorm.objects.filter(Header__id=qp.id).exists(): .... </code></pre> <blockquote> Returns <code>True</code> if the QuerySet contains any results, and <code>False</code> if not. This tries to perform the query in the simplest and fastest way possible, but it does execute nearly the same query as a normal QuerySet query. </blockquote>
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Querying!

Guidance

A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.