Difference between revisions of "JOIN Quiz 2"

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JOIN Quiz - part 2
 
  
<div class='db_ref' style='background:none'>
 
<table class='zoo'>
 
<caption>teacher</caption>
 
<tr>
 
<th>id</th>
 
<th>dept</th>
 
<th>name</th>
 
<th>phone</th>
 
<th>mobile</th>
 
</tr>
 
<tr>
 
<td align='right'>101</td>
 
<td align='right'>1</td>
 
<td>Shrivell</td>
 
<td align='right'>2753</td>
 
<td>07986 555 1234</td>
 
</tr>
 
<tr>
 
<td align='right'>102</td>
 
<td align='right'>1</td>
 
<td>Throd</td>
 
<td align='right'>2754</td>
 
<td>07122 555 1920</td>
 
</tr>
 
<tr><td align='right'>103</td>
 
<td align='right'>1</td>
 
<td>Splint</td>
 
<td align='right'>2293</td>
 
<td></td>
 
</tr>
 
<tr><td align='right'>104</td>
 
<td align='right'></td>
 
<td>Spiregrain</td>
 
<td align='right'>3287</td>
 
<td></td>
 
</tr>
 
<tr>
 
<td align='right'>105</td>
 
<td align='right'>2</td>
 
<td>Cutflower</td>
 
<td align='right'>3212</td>
 
<td>07996 555 6574</td>
 
</tr>
 
<tr>
 
<td align='right'>106</td>
 
<td align='right'></td>
 
<td>Deadyawn</td>
 
<td align='right'>3345</td>
 
<td></td>
 
</tr>
 
</table>
 
<table class='zoo'>
 
<caption>dept</caption>
 
<tr>
 
<th>id</th>
 
<th>name</th>
 
</tr>
 
<tr>
 
<td align='right'>1</td>
 
<td>Computing</td>
 
</tr>
 
<tr>
 
<td align='right'>2</td>
 
<td>Design</td>
 
</tr>
 
<tr>
 
<td align='right'>3</td>
 
<td>Engineering</td>
 
</tr>
 
</table>
 
</div>
 
 
<quiz shuffle=none display=simple>
 
{Which of the following uses of JOIN is correct?
 
|type="()"}
 
- SELECT teacher.name, dept.name FROM teacher JOIN dept ON (dept = id)
 
- SELECT teacher.name, dept.name FROM teacher, dept INNER JOIN ON (teacher.dept = dept.id)
 
- SELECT teacher.name, dept.name FROM teacher, dept JOIN WHERE(teacher.dept = dept.id)
 
- SELECT teacher.name, dept.name FROM teacher OUTER JOIN dept ON dept.id
 
+ SELECT teacher.name, dept.name FROM teacher LEFT OUTER JOIN dept ON (teacher.dept > dept.id)
 
 
{Select the correct statement that shows the name of department which employs Cutflower
 
|type="()"}
 
- SELECT dept.name FROM teacher JOIN dept ON (dept.id = (SELECT dept FROM teacher WHERE name = 'Cutflower'))
 
- SELECT dept.name FROM teacher JOIN dept ON (dept.id = teacher.dept) WHERE dept.id = (SELECT dept FROM teacher HAVING name = 'Cutflower')
 
+ SELECT dept.name FROM teacher JOIN dept ON (dept.id = teacher.dept) WHERE teacher.name = 'Cutflower'
 
- SELECT dept.name FROM teacher JOIN dept WHERE dept.id = (SELECT dept FROM teacher WHERE name = 'Cutflower')
 
- SELECT name FROM teacher JOIN dept ON (id = dept) WHERE id = (SELECT dept FROM teacher WHERE name = 'Cutflower')
 
 
 
{Using <code>SELECT name, dept, COALESCE(dept, 0) AS result FROM teacher</code> on <code>teacher</code> table will:
 
|type="()"}
 
- display 0 in result column for all teachers
 
+ display 0 in result column for all teachers without department
 
- do nothing - the statement is incorrect
 
- set dept value of all teachers to 0
 
- set dept value of all teachers without department to 0
 
 
</quiz>
 
 
[[Category:Quizzes]]
 

Revision as of 13:44, 18 July 2012

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