chapter ten multiple row functions/join:
DESCRIPTION
Chapter Ten Multiple Row Functions/Join:. Objectives: -Multiple row functions -Ordering -Grouping -Concept of JOIN. Aggregate Functions:. MAX (DISTINCT | ALL) (value) MIN (DISTINCT | ALL) (value) AVG(DISTINCT | ALL) (value) SUM (DISTINCT | ALL) (value) - PowerPoint PPT PresentationTRANSCRIPT
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Chapter TenMultiple Row Functions/Join:Objectives:
-Multiple row functions
-Ordering-Grouping-Concept of JOIN
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Aggregate Functions:
• MAX (DISTINCT | ALL) (value)
• MIN (DISTINCT | ALL) (value)
• AVG (DISTINCT | ALL) (value)
• SUM (DISTINCT | ALL) (value)
• COUNT (DISTINCT | ALL) (value)*
• STDDEV (DISTINCT | ALL) (value)
• VARIANCE (DISTINCT | ALL) (value)
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Aggregate Functions:
• COUNT (*)
• COUNT (id)
• COUNT (DISTINCT ID)
• MAX (Birth_date)
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SUM (exp)
• SUM (exp) [ OVER (analytic_clause) ]
SELECT ID, name, salary,SUM (Salary)
OVER (ORDER BY salary) “Cumulating sum”
FROM Faculty;• NAME SALARY DEPT Cumulating sum
• -------------------------------------------------------------
• Hook 25000 MATH 25000
• Johnson 30000 MATH 55000
• Williams 34000 COSC 89000
• Jackson 45000 COSC 134000
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SUM (exp)
SELECT ID, name, salary, SUM (Salary) OVER (PARTITION BY Dept ORDER BY salary) “Cumulating sum”
FROM Faculty;• NAME SALARY DEPT Cumulating sum
• ------------------------------------------------------------------
• William 34000 COSC 34000
• Jackson 45000 COSC 79000
• Hook 25000 MATH 25000
• Johnson 30000 MATH 55000
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Aggregate Functions:
• List the highest GPA
SELECT MAX (GPA)
FROM Student;
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Aggregate Functions:
• List average, max, min, and total salary of cosc faculty
SELECT AVG(salary), MIN(salary),
MAX(salary), SUM(salary)
FROM faculty
WHERE dept = ‘COSC’;
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Aggregate Functions:
• List average salary of cosc faculty:
SELECT AVG(NVL(salary,0)),
AVG (salary), COUNT(*)
FROM faculty
WHERE dept = ‘COSC’;
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Aggregate Functions:
• LEAD: Access to more than one row• List faculty with the hired date and the
next hired date after each one• SELECT name, hired_date,
LEAD(hired_date,1) OVER(ORDER BY
hired_date) AS “next hired”
FROM faculty;
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• RANK (exp, exp, …) WITHIN GROUP• RANK ( ) OVER ( [partition] ORDER BY)
SELECT RANK(24000) WITHIN GROUP(ORDER BY Salary DESC) “Rank of $24,000
Salary”FROM Faculty;
SELECT RANK(24000, ‘PROFESSOR’) WITHIN GROUP(ORDER BY Salary, P_Rank) “Rank”
FROM Faculty;
SELECT Name, Salary, RANK() OVER (PARTITION BY Dept_Name
ORDER BY Salary, P_Rank) “Rank”FROM FacultyWHERE Dept = ‘COSC’;
Rank:
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Distinct:
SELECT DISTINCT (dept)FROM Faculty;
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User:
SELECT USER, UIDFROM DUAL;
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USERENV:• USERENV (‘Parameter’)
parameters:ENTRYID -- current audit entry numberISDBA -- True if s/he in DBA privilegeLANG -- Language used SESSIONID --Session IDTERMINAL --Operating System ID --for the Terminal of current
session
SELECT USERENV(‘LANG’) ‘Language’FROM DUAL;
LANGUAGE----------------------------AMERICAN_AMERICA.WE8ISO8859P1
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Ordering
• ORDERING: (Default is Ascending ASC)
• List students name in an alphabetic order
SELECT nameFROM studentORDER BY name;
ORDER BY Name , GPA DESC, Major;
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Ordering
• List of the faculty salary for the next year with 5% increase order by new salary.
SELECT name,
salary pay, salary+salary*0.05 AS new_salary
FROM facultyORDER BY new_salary;
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Grouping
SELECT
FROM
[WHERE]
[GROUP BY]
[ORDER BY]
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Grouping
• Average Salary of faculty members by department
SELECT dept, AVG(Salary)
FROM Faculty
GROUP BY dept;
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Grouping
• List number of courses taken by each student
SELECT ID, COUNT(*)
FROM Student_Course
GROUP BY ID;
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Grouping by multiple attributes
• List total number of credits taken by each student
SELECT ID, SUM(Cr)
FROM Student_CourseGROUP BY ID;
SELECT ID, semester, SUM(Cr)FROM Student_CourseGROUP BY ID, semester;
SELECT dept, count(name)FROM facultyGROUP BY dept;
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Having
• Condition on Group:
SELECT
FROM
[WHERE]
[GROUP BY]
[HAVING]
[ORDER BY]
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Having
List ID of students who have more than 20 credits and majoring in COSC.
SELECT ID, SUM (Cr)
FROM Student_Course
WHERE Major = 'COSC'
GROUP BY ID
HAVING SUM(Cr) > 20 ;
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Having
• SELECT dept, MAX(salary)
FROM faculty
GROUP BY Department
HAVING MAX(salary)>50000;
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Having
• SELECT dept, MAX(salary) a
FROM faculty
GROUP BY Dept
HAVING a >50000
ORDER BY MAX(salary);
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Having
• SELECT dept, MAX(SUM(salary))
FROM faculty
GROUP BY dept;
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Illegal Queries:
• SELECT name, count(*) FROM Department;
SELECT name, count(*) FROM Department GROUP BY name;
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Illegal Queries:
SELECT name, AVG(salary) FROM Department WHERE AVG(salary) >5000;
SELECT name, AVG(salary) FROM Department GROUP BY name HAVING AVG(salary) >5000;
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JOIN:
• Definition
• General Format:
• SELECT col1,col2,….
FROM table1, table2,…
WHERE conditions;
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JOIN:
• List of students’ name with the grade = 'A' • SELECT Name
FROM Student_Course, StudentWHERE Student.ID =
Student_Course.ID AND Grade
=‘A’;
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JOIN:
• Aliases:
SELECT Name
FROM Student_Course sc,
Student s
WHERE s.ID = sc.ID AND Grade =‘A’;
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CARTESIAN PRODUCT:
– Join condition is omitted– Join condition is invalid– All rows in table one are joined to all rows in
table two
SELECT *
FROM Student, faculty;
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JOIN
• Equijoin/Natural:
SELECT NameFROM Student_Course, StudentWHERE Student.ID = Student_Course.ID ;
SELECT NameFROM Student_Course
NATURAL JOIN Student ;
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JOIN
• Equijoin/Natural:
SELECT Name
FROM Student_Course
INNER JOIN Student ;
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JOIN
• Inner Join:
SELECT a.Name
FROM Student_Course b
INNER JOIN Student a
ON a.ID = b.ID ;
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JOIN
• Equijoin:
SELECT department.num_faculty,faculty.nameFROM department, facultyWHERE department.name=faculty.dept;
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JOIN
• Non-Equijoin:
Faculty (name, salary)Status (rank, low_salry, high_salary)
• Get the name, salary and rank of faculty members
• SELECT name, salary, rankFROM faculty, statusWHERE salary BETWEEN low_salary AND high_salary;
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JOIN
• Outer Join:
List of books that have been checked out:
SELECT DISTINCT title
FROM CheckedBook ;
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JOIN
• Outer Join:
List of books that have not been checked out:
SELECT DISTINCT title
FROM ShelfBook ;
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JOIN
• Outer Join:
List of all books:??SELECT DISTINCT title FROM ShelfBook a,
CheckedBook bWHERE a.ID=b.ID ;
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JOIN
• Outer Join:
List of all books:
SELECT title, MAX(b.R_date-b.C_date)
FROM ShelfBook a,
CheckedBook b
WHERE a.ID (+) = b.ID ;
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JOIN
• ANSI SQL Outer Join:
List of all books:
SELECT DISTINCT title
FROM
ShelfBook b RIGHT OUTER JOIN CheckedBook a ON
a.ID = b.ID ;
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JOIN
• ANSI SQL Outer Join:
List of all books:
SELECT DISTINCT title
FROM
CheckedBook a LEFT OUTER JOIN ShelfBook b ON
a.ID = b.ID ;
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JOIN
• ANSI SQL Outer Join:
List of all books:
SELECT DISTINCT title
FROM
CheckedBook a FULL OUTER JOIN ShelfBook b ON
a.ID = b.ID ;
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JOIN
• Outer Join:
• SELECT department.num_faculty, faculty.name
FROM department, faculty
WHEREdepartment.name(+)=faculty.dept
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JOIN
• Outer Join:
• SELECT department.num_faculty, faculty.name
FROM
department LEFT OUTER JOIN faculty ON department.name=faculty.dept;
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JOIN
• Self Join
SELECT a.Name
FROM Student a, Student b
WHERE a.ID > b.ID AND
b.Name = 'SMITH';
What is the output of this query
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JOIN
• Self Join• List of Faculty member with salary higher than
salary of Mary and less than salary of John SELECT a.Name
FROM Faculty a, Faculty b, Faculty cWHERE a.Salary > b.Salary AND
a.Salary < c.Salary ANDb.Name = 'MARY' ANDc.Name = 'JOHN’;