Add notes for 2018-09-24

content/posts/2018-09.md

@@ -401,4 +401,34 @@ dspace=# select item_id from item where in_archive is True and withdrawn is Fals
 - Also, I need to test the new LDAP server, so I will deploy that on DSpace Test today
 - Rename my cgspace-statistics-api to [dspace-statistics-api](https://github.com/alanorth/dspace-statistics-api) on GitHub
 
+## 2018-09-24
+
+- Trying to figure out how to get item views and downloads from SQLite in a join
+- It appears SQLite doesn't support `FULL OUTER JOIN` so some people on StackOverflow have emulated it with `LEFT JOIN` and `UNION`:
+
+```
+> SELECT views.views, views.id, downloads.downloads, downloads.id FROM itemviews views
+LEFT JOIN itemdownloads downloads USING(id)
+UNION ALL
+SELECT views.views, views.id, downloads.downloads, downloads.id FROM itemdownloads downloads
+LEFT JOIN itemviews views USING(id)
+WHERE views.id IS NULL;
+```
+
+- This "works" but the resulting rows are kinda messy so I'd have to do extra logic in Python
+- Maybe we can use one "items" table with defaults values and UPSERT (aka insert... on conflict ... do update):
+
+```
+sqlite> CREATE TABLE items(id INT PRIMARY KEY, views INT DEFAULT 0, downloads INT DEFAULT 0);
+sqlite> INSERT INTO items(id, views) VALUES(0, 52);
+sqlite> INSERT INTO items(id, downloads) VALUES(1, 171);
+sqlite> INSERT INTO items(id, downloads) VALUES(1, 176) ON CONFLICT(id) DO UPDATE SET downloads=176;
+sqlite> INSERT INTO items(id, views) VALUES(0, 78) ON CONFLICT(id) DO UPDATE SET views=78;
+sqlite> INSERT INTO items(id, views) VALUES(0, 3) ON CONFLICT(id) DO UPDATE SET downloads=3;
+sqlite> INSERT INTO items(id, views) VALUES(0, 7) ON CONFLICT(id) DO UPDATE SET downloads=excluded.views;
+```
+
+- This totally works!
+- Note the special `excluded.views` form! See [SQLite's lang_UPSERT documentation](https://www.sqlite.org/lang_UPSERT.html)
+
 <!-- vim: set sw=2 ts=2: -->

docs/2018-09/index.html

@@ -18,7 +18,7 @@ I’m testing the new DSpace 5.8 branch in my Ubuntu 18.04 environment and I
 " />
 <meta property="og:type" content="article" />
 <meta property="og:url" content="https://alanorth.github.io/cgspace-notes/2018-09/" /><meta property="article:published_time" content="2018-09-02T09:55:54&#43;03:00"/>
-<meta property="article:modified_time" content="2018-09-23T16:51:17&#43;03:00"/>
+<meta property="article:modified_time" content="2018-09-24T00:31:59&#43;03:00"/>
 <meta name="twitter:card" content="summary"/>
 <meta name="twitter:title" content="September, 2018"/>
 <meta name="twitter:description" content="2018-09-02
@@ -41,9 +41,9 @@ I&rsquo;m testing the new DSpace 5.8 branch in my Ubuntu 18.04 environment and I
   "@type": "BlogPosting",
   "headline": "September, 2018",
   "url": "https://alanorth.github.io/cgspace-notes/2018-09/",
-  "wordCount": "2893",
+  "wordCount": "3094",
   "datePublished": "2018-09-02T09:55:54&#43;03:00",
-  "dateModified": "2018-09-23T16:51:17&#43;03:00",
+  "dateModified": "2018-09-24T00:31:59&#43;03:00",
   "author": {
     "@type": "Person",
     "name": "Alan Orth"
@@ -576,6 +576,40 @@ $ grep -c -E 'session_id=[A-Z0-9]{32}:ip_addr=50.116.102.77' dspace.log.2018-09-
 <li>Rename my cgspace-statistics-api to <a href="https://github.com/alanorth/dspace-statistics-api">dspace-statistics-api</a> on GitHub</li>
 </ul>
 
+<h2 id="2018-09-24">2018-09-24</h2>
+
+<ul>
+<li>Trying to figure out how to get item views and downloads from SQLite in a join</li>
+<li>It appears SQLite doesn&rsquo;t support <code>FULL OUTER JOIN</code> so some people on StackOverflow have emulated it with <code>LEFT JOIN</code> and <code>UNION</code>:</li>
+</ul>
+
+<pre><code>&gt; SELECT views.views, views.id, downloads.downloads, downloads.id FROM itemviews views
+LEFT JOIN itemdownloads downloads USING(id)
+UNION ALL
+SELECT views.views, views.id, downloads.downloads, downloads.id FROM itemdownloads downloads
+LEFT JOIN itemviews views USING(id)
+WHERE views.id IS NULL;
+</code></pre>
+
+<ul>
+<li>This &ldquo;works&rdquo; but the resulting rows are kinda messy so I&rsquo;d have to do extra logic in Python</li>
+<li>Maybe we can use one &ldquo;items&rdquo; table with defaults values and UPSERT (aka insert&hellip; on conflict &hellip; do update):</li>
+</ul>
+
+<pre><code>sqlite&gt; CREATE TABLE items(id INT PRIMARY KEY, views INT DEFAULT 0, downloads INT DEFAULT 0);
+sqlite&gt; INSERT INTO items(id, views) VALUES(0, 52);
+sqlite&gt; INSERT INTO items(id, downloads) VALUES(1, 171);
+sqlite&gt; INSERT INTO items(id, downloads) VALUES(1, 176) ON CONFLICT(id) DO UPDATE SET downloads=176;
+sqlite&gt; INSERT INTO items(id, views) VALUES(0, 78) ON CONFLICT(id) DO UPDATE SET views=78;
+sqlite&gt; INSERT INTO items(id, views) VALUES(0, 3) ON CONFLICT(id) DO UPDATE SET downloads=3;
+sqlite&gt; INSERT INTO items(id, views) VALUES(0, 7) ON CONFLICT(id) DO UPDATE SET downloads=excluded.views;
+</code></pre>
+
+<ul>
+<li>This totally works!</li>
+<li>Note the special <code>excluded.views</code> form! See <a href="https://www.sqlite.org/lang_UPSERT.html">SQLite&rsquo;s lang_UPSERT documentation</a></li>
+</ul>
+
 <!-- vim: set sw=2 ts=2: -->
 
   

docs/sitemap.xml

@@ -4,7 +4,7 @@
   
   <url>
     <loc>https://alanorth.github.io/cgspace-notes/2018-09/</loc>
-    <lastmod>2018-09-23T16:51:17+03:00</lastmod>
+    <lastmod>2018-09-24T00:31:59+03:00</lastmod>
   </url>
   
   <url>
@@ -184,7 +184,7 @@
   
   <url>
     <loc>https://alanorth.github.io/cgspace-notes/</loc>
-    <lastmod>2018-09-23T16:51:17+03:00</lastmod>
+    <lastmod>2018-09-24T00:31:59+03:00</lastmod>
     <priority>0</priority>
   </url>
   
@@ -195,7 +195,7 @@
   
   <url>
     <loc>https://alanorth.github.io/cgspace-notes/tags/notes/</loc>
-    <lastmod>2018-09-23T16:51:17+03:00</lastmod>
+    <lastmod>2018-09-24T00:31:59+03:00</lastmod>
     <priority>0</priority>
   </url>
   
@@ -207,13 +207,13 @@
   
   <url>
     <loc>https://alanorth.github.io/cgspace-notes/posts/</loc>
-    <lastmod>2018-09-23T16:51:17+03:00</lastmod>
+    <lastmod>2018-09-24T00:31:59+03:00</lastmod>
     <priority>0</priority>
   </url>
   
   <url>
     <loc>https://alanorth.github.io/cgspace-notes/tags/</loc>
-    <lastmod>2018-09-23T16:51:17+03:00</lastmod>
+    <lastmod>2018-09-24T00:31:59+03:00</lastmod>
     <priority>0</priority>
   </url>