A practical approach towards learning SQL in Oracle 11g. Video lectures are prepared as well and can be found at given link https://www.youtube.com/channel/UCMv6HrS_4_GFWmLLFzL_U_A?view_as=subscriber

1. SQL Fundamentals Oracle 11g
M U H A M M A D WA H E E D
O R AC L E DATA BA S E D E V E LO P E R
E M A I L : m .wa h e e d 3 6 6 8 @ g m a i l . co m
Lecture#6
SQL Functions(cont’d)

2. Group Functions
There are following types of group functions
•AVG
•COUNT
•MAX
•MIN
•STDDEV
•SUM
•VARIANCE
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3. Group Functions(cont’d)
3

4. Group Functions(cont’d)
4

5. Grouping Data
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6. Grouping Data(cont’d)
6
Use of GROUP By clause
•All columns specified in SELECT must be in GROUP BY clause
except those in group function.
•Example:
SELECT dept_id , AVG(salary)
FROM employee
GROUP BY dept_id;

7. Grouping Data(cont’d)
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Use of GROUP BY clause
•All columns specified in GROUP BY may not be in SELECT
clause.
•Example:
SELECT AVG(salary)
FROM employee
GROUP BY dept_id;

8. Grouping Data(cont’d)
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9. Grouping Data(cont’d)
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Use of GROUP BY clause on multiple columns
•Example:
SELECT tch_designation,tch_id,AVG(salary)
FROM employee
GROUP BY dept_id, tch_designation;

10. Grouping Data(cont’d)
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Illegal queries are as following:

11. Grouping Data(cont’d)
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Illegal queries are as following:
• You cannot use group functions in WHERE clause

12. Grouping Data(cont’d)
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Use of HAVING clause with group functions
•Example:
SELECT dept_id, MAX(salary)
FROM employee
GROUP BY dept_id
HAVING MAX(salary) >15000;

13. Grouping Data(cont’d)
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Use of multiple clauses with group functions
•Example:
SELECT dept_id, SUM(salary) AS PAYROLL
FROM employee
WHERE tch_designation NOT LIKE ‘%ASSIST%’
GROUP BY tch_designation
HAVING SUM(salary) >15000
ORDER BY SUM(salary);

14. Motivational Speaking
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15. Feedback/Suggestions?
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