Using Null Quiz

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Using Null Quiz

teacher
id dept name phone mobile
101 1 Shrivell 2753 07986 555 1234
102 1 Throd 2754 07122 555 1920
103 1 Splint 2293
104 Spiregrain 3287
105 2 Cutflower 3212 07996 555 6574
106 Deadyawn 3345
...
dept
id name
1 Computing
2 Design
3 Engineering
...

1. Select the code which uses a JOIN correctly.

A. SELECT teacher.name, dept.name FROM teacher JOIN dept ON (dept = id)
B. SELECT teacher.name, dept.name FROM teacher, dept INNER JOIN ON (teacher.dept = dept.id)
C. SELECT teacher.name, dept.name FROM teacher, dept JOIN WHERE(teacher.dept = dept.id)
D. SELECT teacher.name, dept.name FROM teacher OUTER JOIN dept ON dept.id
E. SELECT teacher.name, dept.name FROM teacher LEFT OUTER JOIN dept ON (teacher.dept > dept.id)

2. Select the correct statement that shows the name of department which employs Cutflower

A. SELECT dept.name FROM teacher JOIN dept ON (dept.id = (SELECT dept FROM teacher WHERE name = 'Cutflower'))
B. SELECT dept.name FROM teacher JOIN dept ON (dept.id = teacher.dept) WHERE dept.id = (SELECT dept FROM teacher HAVING name = 'Cutflower')
C. SELECT dept.name FROM teacher JOIN dept ON (dept.id = teacher.dept) WHERE teacher.name = 'Cutflower'
D. SELECT dept.name FROM teacher JOIN dept WHERE dept.id = (SELECT dept FROM teacher WHERE name = 'Cutflower')
E. SELECT name FROM teacher JOIN dept ON (id = dept) WHERE id = (SELECT dept FROM teacher WHERE name = 'Cutflower')

3. Select out of following the code which uses a JOIN to show a list of all the departments and number of employed teachers

A. SELECT dept.name, COUNT(*) FROM teacher LEFT JOIN dept ON dept.id = teacher.dept
B. SELECT dept.name, COUNT(teacher.name) FROM teacher, dept JOIN ON dept.id = teacher.dept GROUP BY dept.name
C. SELECT dept.name, COUNT(teacher.name) FROM teacher JOIN dept ON dept.id = teacher.dept GROUP BY dept.name
D. SELECT dept.name, COUNT(teacher.name) FROM teacher LEFT OUTER JOIN dept ON dept.id = teacher.dept GROUP BY dept.name
E. SELECT dept.name, COUNT(teacher.name) FROM teacher RIGHT JOIN dept ON dept.id = teacher.dept GROUP BY dept.name

4. Using SELECT name, dept, COALESCE(dept, 0) AS result FROM teacher on teacher table will:

A. display 0 in result column for all teachers
B. display 0 in result column for all teachers without department
C. do nothing - the statement is incorrect
D. set dept value of all teachers to 0
E. set dept value of all teachers without department to 0

5. Query: SELECT name, CASE WHEN phone = 2752 THEN 'two' WHEN phone = 2753 THEN 'three' WHEN phone = 2754 THEN 'four' END AS digit FROM teacher shows following 'digit':

A. 'four' for Throd
B. NULL for all teachers
C. NULL for Shrivell
D. 'two' for Cutflower
E. 'two' for Deadyawn

Your score is 0 / 0
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