Aggregates with DISTINCT - Revision history

Connor at 08:23, 18 July 2012

2012-07-18T08:23:28Z

Connor at 09:59, 11 July 2012

2012-07-11T09:59:56Z

Connor: Created page with "

Nobel database

COUNT DISTINCT

You can find the number of different values using COUNT with DISTINCT

In 1915 four prizes were award..."

2012-07-11T09:51:09Z

Created page with " <h3>Nobel database</h3> <h2>COUNT DISTINCT</h2> <p>You can find the number of <i>different</i> values using COUNT with DISTINCT</p> <p>In 1915 four prizes were award..."

New page

<h3>Nobel database</h3>

<h2>COUNT DISTINCT</h2>

<p>You can find the number of <i>different</i> values using COUNT with DISTINCT</p>
<p>In 1915 four prizes were awarded in three different subjects:</p>
<table><tr><td><pre>SELECT yr, subject, winner
FROM nobel
WHERE yr=1915</pre>
</td><td>
<table border="1" class="restable" style=""><tr>
<th>yr</th>
<th>subject</th>
<th>winner</th>
</tr>
<tr>
<td align="right">1915</td>
<td>Chemistry</td>
<td>Richard Willstätter</td>
</tr>
<tr>
<td align="right">1915</td>
<td>Literature</td>
<td>Romain Rolland</td>
</tr>
<tr>
<td align="right">1915</td>
<td>Physics</td>
<td>Lawrence Bragg</td>
</tr>
<tr>
<td align="right">1915</td>
<td>Physics</td>
<td>William Bragg</td>
</tr>
</table></td></tr>
</table>

<div class='qu'>
COUNT(subject) gives 4; COUNT(DISTINCT subject) gives 3.
<source lang='sql' class='def'>
SELECT COUNT(subject), COUNT(DISTINCT subject)
FROM nobel
WHERE yr = 1915
</source>

<source lang='sql' class='ans'>
SELECT COUNT(subject), COUNT(DISTINCT subject)
FROM nobel
WHERE yr = 1915'
</source>
</div>

@@ Line 5: / Line 5: @@
    <p>You can find the number of <i>different</i> values using COUNT with DISTINCT</p>
    <p>In 1915 four prizes were awarded in three different subjects:</p>
-<table><td><pre>SELECT yr, subject, winner
+<table class='NoBorder'><td><pre>SELECT yr, subject, winner
    FROM nobel
   WHERE yr=1915</pre>
 </td><td>
-<table border="1" class="restable" style=""><tr>
+<table border="1" class="Bordered" style=""><tr>
 <th>yr</th>
 <th>subject</th>

@@ Line 5: / Line 5: @@
    <p>You can find the number of <i>different</i> values using COUNT with DISTINCT</p>
    <p>In 1915 four prizes were awarded in three different subjects:</p>
-<table><tr><td><pre>SELECT yr, subject, winner
+<table><td><pre>SELECT yr, subject, winner
    FROM nobel
   WHERE yr=1915</pre>
@@ Line 34: / Line 34: @@
 <td>William Bragg</td>
 </tr>
-</table></td></tr>
+</table></td>
 </table>
@@ Line 48: / Line 48: @@
 SELECT COUNT(subject), COUNT(DISTINCT subject)
    FROM nobel
-  WHERE yr = 1915'
+  WHERE yr = 1915
 </source>
 </div>