Congestion Charging - Revision history

Andr3w at 09:32, 5 May 2013

2013-05-05T09:32:31Z

Asidirop at 09:55, 12 December 2012

2012-12-12T09:55:55Z

Connor at 12:49, 19 July 2012

2012-07-19T12:49:25Z

Connor: Created page with "

Congestion charging database

Graduated questions

[[Congestion Easy |Easy questions: 1..5
[[Congestion Medium |Medium questions: 6..10

2012-07-19T12:45:08Z

Created page with "<h1>Congestion charging database</h1> <p>Graduated questions</p> <ul> <li>[[Congestion Easy |Easy questions: 1..5</li> <li>[[Congestion Medium |Medium questions: 6..10</li> ..."

New page

<h1>Congestion charging database</h1>
<p>Graduated questions</p>
<ul>
<li>[[Congestion Easy |Easy questions: 1..5</li>
<li>[[Congestion Medium |Medium questions: 6..10</li>
<li>[[Congestion Hard |Hard questions: 11..15</li>
</ul>
<p>ER diagram for the Congestion charging database:</p>
[[Image:/pics/er5.gif]]
<p>camera(id, perim)</p>
<p>keeper(id, name, address)</p>
<p>vehicle(id, keeper)</p>
<p>image(camera, whn, reg)</p>
<p>permit(reg, sDate, chargeType)</p>
<h2>Sample query</h2>

<div class='qu'>
List the vehicles for which 'Strenuous, Sam' is the registered keeper.
The link between Keepers and Vehicles is via the foreign key specified in the CREATE TABLE vehicle statement. Note the line:
,FOREIGN KEY(keeper) REFERENCES keeper(id)
This will be the basis of our join condition.
<source lang='sql' class='def'>
SELECT vehicle.id
FROM vehicle JOIN keeper
ON vehicle.keeper = keeper.id
WHERE keeper.name = 'Strenuous, Sam'
</source>
</div>

@@ Line 7: / Line 7: @@
 </ul>
 <p>ER diagram for the Congestion charging database:</p>
-[[Image:/pics/er5.gif]]
+[[Image:CongestionChargeER.gif]]
-−
-[[File:/pics/er5.gif]]
 <p>camera(id, perim)</p>
 <p>keeper(id, name, address)</p>

@@ Line 2: / Line 2: @@
 <p>Graduated questions</p>
 <ul>
-  <li>[[Congestion Easy |Easy questions: 1..5</li>
+  <li>[[Congestion Easy |Easy questions: 1..5]]</li>
-  <li>[[Congestion Medium |Medium questions: 6..10</li>
+  <li>[[Congestion Medium |Medium questions: 6..10]]</li>
-  <li>[[Congestion Hard |Hard questions: 11..15</li>
+  <li>[[Congestion Hard |Hard questions: 11..15]]</li>
 </ul>
 <p>ER diagram for the Congestion charging database:</p>