SQL select values sum by same ID - sql

here is my table called "Employee"
eID | name |
==============
1 | Mike |
2 | Josh |
3 | Mike |
And table called "Sells"
sID | eID | | price |
=========================
1 | 1 | | 8 |
2 | 3 | | 9 |
3 | 3 | | 5 |
4 | 1 | | 4 |
5 | 1 | | 3 |
This should be my expected result: returns the total income per employee
name | Income |
==================
Mike | 15 |
Josh | 0 |
Mike | 14 |
Actually, I know use the query "SUM...GROUP BY..." to get the incomes of 15 and 14, but I don't know how to get the income of 0 which is not shown on the "Sells" table.
Could someone give me some help? Thanks a lot.


You just need to use a left outer join, so you can get the sum for missing values too. You could use case expression to deal with null values
SELECT e.name,
COALESCE(SUM(price), 0) as Income
FROM employees e
LEFT OUTER JOIN sells s
ON e.eid = s.eid
GROUP BY e.eid, e.name
Edited: case expression is not needed. I put coalesce on the return of sum fuction, in order to deal with missing values (SUM over an empty set returns NULL)

Related

Trying to join a table of individuals to a table of couples, give a family ID and not time out the server

I have one table with fake individual tax records like so (one row per filer):
T1:
+-------+---------+---------+
| Person| Spouse | Income |
+-------+---------+---------+
| 1 | 2 | 34000 |
| 2 | 1 | 10000 |
| 3 | NULL | 97000 |
| 4 | 6 | 11000 |
| 5 | NULL | 25000 |
| 6 | 4 | 100000 |
+-------+---------+---------+
I have a second table which has tax 'families', a single individual or married couple (one line per tax 'family').
T1_Family:
+-------- -+-------+---------+
| Family_id| Person| Spouse |
+-------- -+-------+---------+
| 2 | 2 | 1 |
| 3 | 3 | NULL |
| 5 | 5 | NULL |
| 6 | 6 | 4 |
+------ ---+-------+---------+
Family = max(Person) within a couple
The idea of joining the two is for example, to sum the income of 2 people in one tax family (aggregate to the family level).
So, I've tried the following:
select *
into family_table
from
(
(select * from T1_family)a
join
(select * from T1)b
on a.family = b.person **or a.spouse = b.person**
)
where family_id is not null and person is not null
What I should get (and I do get when I select 1 random couple) is one line per individual where I can then group by family_id and sum income, pension contributions, etc. BUT SQL times out before the tables can be joined. The part in bold is what's slowing down the process but I'm not sure what else to do.
Is there an easier way to group by family?

It is simpler to put the data on one row:
select a.*, p.income as person_income, s.income as spouse_income
into family_table
from t1_family a left join
t1 p
on a.person = p.person lef tjoin
t1 s
on a.spouse = s.person;
Of course, you can add them together as well.

How to print the students name in this query?

The concerned tables are as follows:
students(rollno, name, deptcode)
depts(deptcode, deptname)
course(crs_rollno, crs_name, marks)
The query is
Find the name and roll number of the students from each department who obtained
highest total marks in their own department.
Consider:
i) Courses of different department are different.
ii) All students of a particular department take same number and same courses.
Then only the query makes sense.
I wrote a successful query for displaying the maximum total marks by a student in each department.
select do.deptname, max(x.marks) from students so
inner join depts do
on do.deptcode=so.deptcode
inner join(
select s.name as name, d.deptname as deptname, sum(c.marks) as marks from students s
inner join crs_regd c
on s.rollno=c.crs_rollno
inner join depts d
on d.deptcode=s.deptcode
group by s.name,d.deptname) x
on x.name=so.name and x.deptname=do.deptname group by do.deptname;
But as mentioned I need to display the name as well. Accordingly if I include so.name in select list, I need to include it in group by clause and the output is as below:
Kendra Summers Computer Science 274
Stewart Robbins English 80
Cole Page Computer Science 250
Brian Steele English 83
expected output:
Kendra Summers Computer Science 274
Brian Steele English 83
Where is the problem?

I guess this can be easily achieved if you use window function -
select name, deptname, marks
from (select s.name as name, d.deptname as deptname, sum(c.marks) as marks,
row_number() over(partition by d.deptname order by sum(c.marks) desc) rn
from students s
inner join crs_regd c on s.rollno=c.crs_rollno
inner join depts d on d.deptcode=s.deptcode
group by s.name,d.deptname) x
where rn = 1;

To solve the problem with a readable query I had to define a couple of views:
total_marks: For each student the sum of their marks
create view total_marks as select s.deptcode, s.name, s.rollno, sum(c.marks) as total from course c, students s where s.rollno = c.crs_rollno group by s.rollno;
dept_max: For each department the highest total score by a single student of that department
create view dept_max as select deptcode, max(total) max_total from total_marks group by deptcode;
So I can get the desidered output with the query
select a.deptcode, a.rollno, a.name from total_marks a join dept_max b on a.deptcode = b.deptcode and a.total = b.max_total
If you don't want to use views you can replace their selects on the final query, which will result in this:
select a.deptcode, a.rollno, a.name
from
(select s.deptcode, s.name, s.rollno, sum(c.marks) as total from course c, students s where s.rollno = c.crs_rollno group by s.rollno) a
join (select deptcode, max(total) max_total from (select s.deptcode, s.name, s.rollno, sum(c.marks) as total from course c, students s where s.rollno = c.crs_rollno group by s.rollno) a_ group by deptcode) b
on a.deptcode = b.deptcode and a.total = b.max_total
Which I'm sure it is easily improvable in performance by someone more skilled then me...
If you (and anybody else) want to try it the way I did, here is the schema:
create table depts ( deptcode int primary key auto_increment, deptname varchar(20) );
create table students ( rollno int primary key auto_increment, name varchar(20) not null, deptcode int, foreign key (deptcode) references depts(deptcode) );
create table course ( crs_rollno int, crs_name varchar(20), marks int, foreign key (crs_rollno) references students(rollno) );
And here all the entries I inserted:
insert into depts (deptname) values ("Computer Science"),("Biology"),("Fine Arts");
insert into students (name,deptcode) values ("Turing",1),("Jobs",1),("Tanenbaum",1),("Darwin",2),("Mendel",2),("Bernard",2),("Picasso",3),("Monet",3),("Van Gogh",3);
insert into course (crs_rollno,crs_name,marks) values
(1,"Algorithms",25),(1,"Database",28),(1,"Programming",29),(1,"Calculus",30),
(2,"Algorithms",24),(2,"Database",22),(2,"Programming",28),(2,"Calculus",19),
(3,"Algorithms",21),(3,"Database",27),(3,"Programming",23),(3,"Calculus",26),
(4,"Zoology",22),(4,"Botanics",28),(4,"Chemistry",30),(4,"Anatomy",25),(4,"Pharmacology",27),
(5,"Zoology",29),(5,"Botanics",27),(5,"Chemistry",26),(5,"Anatomy",25),(5,"Pharmacology",24),
(6,"Zoology",18),(6,"Botanics",19),(6,"Chemistry",22),(6,"Anatomy",23),(6,"Pharmacology",24),
(7,"Sculpture",26),(7,"History",25),(7,"Painting",30),
(8,"Sculpture",29),(8,"History",24),(8,"Painting",30),
(9,"Sculpture",21),(9,"History",19),(9,"Painting",25) ;
Those inserts will load these data:
select * from depts;
+----------+------------------+
| deptcode | deptname |
+----------+------------------+
| 1 | Computer Science |
| 2 | Biology |
| 3 | Fine Arts |
+----------+------------------+
select * from students;
+--------+-----------+----------+
| rollno | name | deptcode |
+--------+-----------+----------+
| 1 | Turing | 1 |
| 2 | Jobs | 1 |
| 3 | Tanenbaum | 1 |
| 4 | Darwin | 2 |
| 5 | Mendel | 2 |
| 6 | Bernard | 2 |
| 7 | Picasso | 3 |
| 8 | Monet | 3 |
| 9 | Van Gogh | 3 |
+--------+-----------+----------+
select * from course;
+------------+--------------+-------+
| crs_rollno | crs_name | marks |
+------------+--------------+-------+
| 1 | Algorithms | 25 |
| 1 | Database | 28 |
| 1 | Programming | 29 |
| 1 | Calculus | 30 |
| 2 | Algorithms | 24 |
| 2 | Database | 22 |
| 2 | Programming | 28 |
| 2 | Calculus | 19 |
| 3 | Algorithms | 21 |
| 3 | Database | 27 |
| 3 | Programming | 23 |
| 3 | Calculus | 26 |
| 4 | Zoology | 22 |
| 4 | Botanics | 28 |
| 4 | Chemistry | 30 |
| 4 | Anatomy | 25 |
| 4 | Pharmacology | 27 |
| 5 | Zoology | 29 |
| 5 | Botanics | 27 |
| 5 | Chemistry | 26 |
| 5 | Anatomy | 25 |
| 5 | Pharmacology | 24 |
| 6 | Zoology | 18 |
| 6 | Botanics | 19 |
| 6 | Chemistry | 22 |
| 6 | Anatomy | 23 |
| 6 | Pharmacology | 24 |
| 7 | Sculpture | 26 |
| 7 | History | 25 |
| 7 | Painting | 30 |
| 8 | Sculpture | 29 |
| 8 | History | 24 |
| 8 | Painting | 30 |
| 9 | Sculpture | 21 |
| 9 | History | 19 |
| 9 | Painting | 25 |
+------------+--------------+-------+
I take chance to point out that this database is badly designed. This becomes evident with course table. For these reasons:
The name is singular
This table does not represent courses, but rather exams or scores
crs_name should be a foreign key referencing the primary key of another table (that would actually represent the courses)
There is no constrains to limit the marks to a range and to avoid a student to take twice the same exam
I find more logical to associate courses to departments, instead of student to departments (this way also would make these queries easier)
I tell you this because I understood you are learning from a book, so unless the book at one point says "this database is poorly designed", do not take this exercise as example to design your own!
Anyway, if you manually resolve the query with my data you will come to this results:
+----------+--------+---------+
| deptcode | rollno | name |
+----------+--------+---------+
| 1 | 1 | Turing |
| 2 | 6 | Bernard |
| 3 | 8 | Monet |
+----------+--------+---------+
As further reference, here the contents of the views I needed to define:
select * from total_marks;
+----------+-----------+--------+-------+
| deptcode | name | rollno | total |
+----------+-----------+--------+-------+
| 1 | Turing | 1 | 112 |
| 1 | Jobs | 2 | 93 |
| 1 | Tanenbaum | 3 | 97 |
| 2 | Darwin | 4 | 132 |
| 2 | Mendel | 5 | 131 |
| 2 | Bernard | 6 | 136 |
| 3 | Picasso | 7 | 81 |
| 3 | Monet | 8 | 83 |
| 3 | Van Gogh | 9 | 65 |
+----------+-----------+--------+-------+
select * from dept_max;
+----------+-----------+
| deptcode | max_total |
+----------+-----------+
| 1 | 112 |
| 2 | 136 |
| 3 | 83 |
+----------+-----------+
Hope I helped!

Try the following query
select a.name, b.deptname,c.marks
from students a
, crs_regd b
, depts c
where a.rollno = b.crs_rollno
and a.deptcode = c.deptcode
and(c.deptname,b.marks) in (select do.deptname, max(x.marks)
from students so
inner join depts do
on do.deptcode=so.deptcode
inner join (select s.name as name
, d.deptname as deptname
, sum(c.marks) as marks
from students s
inner join crs_regd c
on s.rollno=c.crs_rollno
inner join depts d
on d.deptcode=s.deptcode
group by s.name,d.deptname) x
on x.name=so.name
and x.deptname=do.deptname
group by do.deptname
)
Inner/Sub query will fetch the course name and max marks and the outer query gets the corresponding name of the student.
try and let know if you got the desired result

Dense_Rank() function would be helpful in this scenario:
SELECT subquery.*
FROM (SELECT Student_Total_Marks.rollno,
Student_Total_Marks.name,
Student_Total_Marks.deptcode, depts.deptname,
rank() over (partition by deptcode order by total_marks desc) Student_Rank
FROM (SELECT Stud.rollno,
Stud.name,
Stud.deptcode,
sum(course.marks) total_marks
FROM students stud inner join course course on stud.rollno = course.crs_rollno
GROUP BY stud.rollno,Stud.name,Stud.deptcode) Student_Total_Marks,
dept dept
WHERE Student_Total_Marks.deptcode = dept.deptname
GROUP BY Student_Total_Marks.deptcode) subquery
WHERE suquery.student_rank = 1

Oracle SQL newbie - Add new column that gets occurrence and computations

This post is enhanced version of my previous post here.
Please Note: This is not duplicate post or thread.
I have 3 tables:
1. REQUIRED_AUDITS (Independent table)
2. SCORE_ENTRY (SCORE_ENTRY is One to Many relationship with ERROR table)
3. ERROR
Below are the dummy data and table structure:
REQUIRED_AUDITS TABLE
+-------+------+----------+---------------+-----------------+------------+----------------+---------+
| ID | VP | Director | Manager | Employee | Req_audits | Audit_eligible | Quarter |
+-------+------+----------+---------------+-----------------+------------+----------------+---------+
| 10001 | John | King | susan#com.com | jake#com.com | 2 | Y | FY18Q1 |
| 10002 | John | King | susan#com.com | beth#com.com | 4 | Y | FY18Q1 |
| 10003 | John | Maria | tony#com.com | david#com.com | 6 | N | FY18Q1 |
| 10004 | John | Maria | adam#com.com | william#com.com | 3 | Y | FY18Q1 |
| 10005 | John | Smith | alex#com.com | rose#com.com | 6 | Y | FY18Q1 |
+-------+------+----------+---------------+-----------------+------------+----------------+---------+
SCORE_ENTRY TABLE
+----------------+------+----------+---------------+-----------------+-------+---------+
| SCORE_ENTRY_ID | VP | Director | Manager | Employee | Score | Quarter |
+----------------+------+----------+---------------+-----------------+-------+---------+
| 1 | John | King | susan#com.com | jake#com.com | 100 | FY18Q1 |
| 2 | John | King | susan#com.com | jake#com.com | 90 | FY18Q1 |
| 3 | John | King | susan#com.com | beth#com.com | 98.45 | FY18Q1 |
| 4 | John | King | susan#com.com | beth#com.com | 95 | FY18Q1 |
| 5 | John | King | susan#com.com | beth#com.com | 100 | FY18Q1 |
| 6 | John | King | susan#com.com | beth#com.com | 100 | FY18Q1 |
| 7 | John | Maria | adam#com.com | william#com.com | 99 | FY18Q1 |
| 8 | John | Maria | adam#com.com | william#com.com | 98.1 | FY18Q1 |
| 9 | John | Smith | alex#com.com | rose#com.com | 96 | FY18Q1 |
| 10 | John | Smith | alex#com.com | rose#com.com | 100 | FY18Q1 |
+----------------+------+----------+---------------+-----------------+-------+---------+
ERROR TABLE
+----------+-----------------------------+----------------+
| ERROR_ID | ERROR | SCORE_ENTRY_ID |
+----------+-----------------------------+----------------+
| 10 | Words Missing | 2 |
| 11 | Incorrect document attached | 2 |
| 12 | No results | 3 |
| 13 | Value incorrect | 4 |
| 14 | Words Missing | 4 |
| 15 | No files attached | 4 |
| 16 | Document read error | 7 |
| 17 | Garbage text | 8 |
| 18 | No results | 8 |
| 19 | Value incorrect | 9 |
| 20 | No files attached | 9 |
+----------+-----------------------------+----------------+
I have query that give below output:
+----------+---------------+------------------+------------------+------------------+
| | | Director Summary | | |
+----------+---------------+------------------+------------------+------------------+
| Director | Manager | Audits Required | Audits Performed | Percent Complete |
| King | susan#com.com | 6 | 6 | 100% |
| Maria | adam#com.com | 3 | 2 | 67% |
| Smith | alex#com.com | 6 | 2 | 33% |
+----------+---------------+------------------+------------------+------------------+
Now I would like to add column where I want the number of scores that have an error associated with them divided by total count of scores:
It's not total count of errors divided by count of scores. Instead its count of each occurrence of error and divide by count of score. Please find below example:
Considering
Director:King
Manager:susan#com.com
From SCORE_ENTRY TABLE and ERROR table,
King has 6 entries in SCORE_ENTRY TABLE
6 entries in ERROR TABLE
Instead of 6 entries in ERROR TABLE, I would like to have occurrence of error ie., 3 errors.
Formula to calculate Quality:
Quality = 1 - (sum of error occurrence / total score)*100
For King:
Quality = 1 - (3/6)*100
Quality = 50
Please Note: It's not 1 - (6/6)*100
For Maria:
Quality = 1 - (2/2)*100
Quality = 0
Below is the new output I need with new column called Quality:
+----------+---------------+---------+------------------+------------------+------------------+
| | | | Director Summary | | |
+----------+---------------+---------+------------------+------------------+------------------+
| Director | Manager | Quality | Audits Required | Audits Performed | Percent Complete |
| King | susan#com.com | 50% | 6 | 6 | 100% |
| Maria | adam#com.com | 0% | 3 | 2 | 67% |
| Smith | alex#com.com | 50% | 6 | 2 | 33% |
+----------+---------------+---------+------------------+------------------+------------------+
Below is the query am having (Thanks to #Kaushik Nayak, #APC and others) and need to add new column to this query:
WITH aud(manager_email, director, quarter, total_audits_required)
AS (SELECT manager_email,
director,
quarter,
SUM (CASE
WHEN audit_eligible = 'Y' THEN required_audits
END)
FROM required_audits
GROUP BY manager_email,
director,
quarter), --Total_audits
scores(manager_email, director, quarter, audits_completed)
AS (SELECT manager_email,
director,
quarter,
Count (score)
FROM oq_score_entry s
GROUP BY manager_email,
director,
quarter) --Audits_Performed
SELECT a.director,
a.manager_email manager,
a.total_audits_required,
s.audits_completed,
Round(( ( s.audits_completed ) / ( a.total_audits_required ) * 100 ), 2)
percentage_complete,
a.quarter
FROM aud a
left outer join scores s
ON a.manager_email = s.manager_email
WHERE ( :P4_MANAGER_EMAIL = a.manager_email
OR :P4_MANAGER_EMAIL IS NULL )
AND ( :P4_DIRECTOR = a.director
OR :P4_DIRECTOR IS NULL )
AND ( :P4_QUARTER = a.quarter
OR :P4_QUARTER IS NULL )
ORDER BY a.total_audits_required DESC nulls last
Please let me know if its confusing or need more details. Am open for any suggestions and feedback.
Appreciate any help.
Thanks,
Richa

Update:
Well my first guess has been wrong, and I hope now I'm getting it right.
According to your and shawnt00's comments, you need to compute the count of score entries that have corresponding entries in ERROR table, and use it in quality calculation.
This count you get with the expression:
COUNT ((select max(1) from "ERROR" o where o.score_entry_id=s.score_entry_id)) AS error_occurences
max(1) returns 1 when there is an entry in "ERROR" and NULL otherwise. COUNT skips nulls.
I hope this is clear.
Quality is computed as
(1 - error_occurences/audits_completed)*100%
Below is the full script, where manager_email renamed to manager and oq_score_entry renamed to score_entry.
This is in accordance with your scheme. Also I removed unnecessary WITH column mapping, it just complicates things in this case.
WITH aud AS (SELECT manager, director, quarter, SUM (CASE
WHEN audit_eligible = 'Y' THEN req_audits
END) total_audits_required
FROM required_audits
GROUP BY manager, director, quarter), --Total_audits
scores AS (
SELECT manager, director, quarter,
Count (score) audits_completed,
COUNT ((select max(1) from "ERROR" o where o.score_entry_id=s.score_entry_id)
) error_occurences -- ** Added **
FROM score_entry s
GROUP BY manager, director, quarter
) --Audits_Performed
SELECT a.director,
a.manager manager,
a.total_audits_required,
s.audits_completed,
Round(( 1 - ( s.error_occurences ) / ( s.audits_completed )) * 100, 2), -- ** Added **
Round(( ( s.audits_completed ) / ( a.total_audits_required ) * 100 ), 2)
percentage_complete,
a.quarter
FROM aud a
left outer join scores s ON a.manager = s.manager
WHERE ( :P4_manager = a.manager
OR :P4_manager IS NULL )
AND ( :P4_DIRECTOR = a.director
OR :P4_DIRECTOR IS NULL )
AND ( :P4_QUARTER = a.quarter
OR :P4_QUARTER IS NULL )
ORDER BY a.total_audits_required DESC nulls last
About total_errors:
To add this column you can either use a technique similar to the one used before in scores:
scores AS (
SELECT manager, director, quarter,
count (score) audits_completed,
count ((select max(1) from "ERROR" o where o.score_entry_id=s.score_entry_id )
) error_occurences,
sum ( ( SELECT count(*) from "ERROR" o where o.score_entry_id=s.score_entry_id )
) total_errors -- summing error counts for matched score_entry_ids
FROM score_entry s
GROUP BY manager, director, quarter
)
Or you can rewrite the scores CTE joining score_entry and error, and that would require using DISTINCT on score_entry fields to avoid duplication of rows:
scores AS (
SELECT manager, director, quarter,
count(DISTINCT s.score_entry_id) audits_completed,
count(DISTINCT e.score_entry_id ) error_occurences, -- counting distinct score_entry_ids present in Error
count(e.score_entry_id) total_errors -- counting total rows in Error
FROM score_entry s
LEFT JOIN "ERROR" e ON s.score_entry_id=e.score_entry_id
GROUP BY manager, director, quarter
)
The latter approach is a bit less maintable, since it requires to be careful about unwanted duplication.
Yet another (and may be the most proper) way is to make a separate(third) CTE, but I don't think the query is complex enough to warrant this.
Original answer:
I might be wrong, but it seems to me that by "count of each occurrence of error" you are trying to describe COUNT(DISTINCT expr). That is to count unique occurences of error for each (manager_email, director, quarter).
If so, change the query a bit:
WITH aud(manager_email, director, quarter, total_audits_required)
AS (SELECT manager_email,
director,
quarter,
SUM (CASE
WHEN audit_eligible = 'Y' THEN required_audits
END)
FROM required_audits
GROUP BY manager_email,
director,
quarter), --Total_audits
scores(manager_email, director, quarter, audits_completed, distinct_errors)
AS (SELECT manager_email,
director,
quarter,
Count (score),
COUNT (DISTINCT o.error_id) -- ** Added **
FROM oq_score_entry s join error o on o.score_entry_id=s.score_entry_id
GROUP BY manager_email,
director,
quarter) --Audits_Performed
SELECT a.director,
a.manager_email manager,
a.total_audits_required,
s.audits_completed,
Round(( ( s.distinct_errors ) / ( s.audits_completed ) * 100 ), 2) quality, -- ** Added **
Round(( ( s.audits_completed ) / ( a.total_audits_required ) * 100 ), 2)
percentage_complete,
a.quarter
FROM aud a
left outer join scores s
ON a.manager_email = s.manager_email
WHERE ( :P4_MANAGER_EMAIL = a.manager_email
OR :P4_MANAGER_EMAIL IS NULL )
AND ( :P4_DIRECTOR = a.director
OR :P4_DIRECTOR IS NULL )
AND ( :P4_QUARTER = a.quarter
OR :P4_QUARTER IS NULL )
ORDER BY a.total_audits_required DESC nulls last

The join on your main query will need to include director and quarter once you have more data.
I suppose the easiest way to fix this is to follow the structure you've got and add another table expression joining it to the rest of your results in the same way as the original two.
select manager_email, director, quarter,
100.0 - 100.0 * count (distinct e.score_entry_id) / count (*) as quality
from score_entry se left outer join error e
on e.score_entry_id = se.score_entry_id
group by manager_email, director, quarter
What would have made most of your explanation unnecessary is to have simply said that you want the number of scores that have an error associated with them. It was difficult to draw that out from the information you provided.

Getting Sum of MasterTable's amount which joins to DetailTable

I have two tables:
1. Master
| ID | Name | Amount |
|-----|--------|--------|
| 1 | a | 5000 |
| 2 | b | 10000 |
| 3 | c | 5000 |
| 4 | d | 8000 |
2. Detail
| ID |MasterID| PID | Qty |
|-----|--------|-------|------|
| 1 | 1 | 1 | 10 |
| 2 | 1 | 2 | 20 |
| 3 | 2 | 2 | 60 |
| 4 | 2 | 3 | 10 |
| 5 | 3 | 4 | 100 |
| 6 | 4 | 1 | 20 |
| 7 | 4 | 3 | 40 |
I want to select sum(Amount) from Master which joins to Deatil where Detail.PID in (1,2,3)
So I execute the following query:
SELECT SUM(Amount) FROM Master M INNER JOIN Detail D ON M.ID = D.MasterID WHERE D.PID IN (1,2,3)
Result should be 20000. But I am getting 40000
See this fiddle. Any suggestion?

You are getting exactly double the amount because the detail table has two occurences for each of the PIDs in the WHERE clause.
See demo
Use
SELECT SUM(Amount)
FROM Master M
WHERE M.ID IN (
SELECT DISTINCT MasterID
FROM DETAIL
WHERE PID IN (1,2,3) )

What is the requirement of joining the master table with details when you have all your columns are in Master table.
Also, isnt there any FK relationhsip defined on these tables. Looking at your data it seems to me that there should be FK on detail table for MasterId. If that is the case then you do not need join the table at all.
Also, in case you want to make sure that you have records in details table for the records for which you need sum and there is no FK relationship. Then you could give a try for exists instead of join.

MySQL: How to select and display ALL rows from one table, and calculate the sum of a where clause on another table?

I'm trying to display all rows from one table and also SUM/AVG the results in one column, which is the result of a where clause. That probably doesn't make much sense, so let me explain.
I need to display a report of all employees...
SELECT Employees.Name, Employees.Extension
FROM Employees;
--------------
| Name | Ext |
--------------
| Joe | 123 |
| Jane | 124 |
| John | 125 |
--------------
...and join some information from the PhoneCalls table...
--------------------------------------------------------------
| PhoneCalls Table |
--------------------------------------------------------------
| Ext | StartTime | EndTime | Duration |
--------------------------------------------------------------
| 123 | 2010-09-05 10:54:22 | 2010-09-05 10:58:22 | 240 |
--------------------------------------------------------------
SELECT Employees.Name,
Employees.Extension,
Count(PhoneCalls.*) AS CallCount,
AVG(PhoneCalls.Duration) AS AverageCallTime,
SUM(PhoneCalls.Duration) AS TotalCallTime
FROM Employees
LEFT JOIN PhoneCalls ON Employees.Extension = PhoneCalls.Extension
GROUP BY Employees.Extension;
------------------------------------------------------------
| Name | Ext | CallCount | AverageCallTime | TotalCallTime |
------------------------------------------------------------
| Joe | 123 | 10 | 200 | 2000 |
| Jane | 124 | 20 | 250 | 5000 |
| John | 125 | 3 | 100 | 300 |
------------------------------------------------------------
Now I want to filter out some of the rows that are included in the SUM and AVG calculations...
WHERE PhoneCalls.StartTime BETWEEN "2010-09-12 09:30:00" AND NOW()
...which will ideally result in a table looking something like this:
------------------------------------------------------------
| Name | Ext | CallCount | AverageCallTime | TotalCallTime |
------------------------------------------------------------
| Joe | 123 | 5 | 200 | 1000 |
| Jane | 124 | 10 | 250 | 2500 |
| John | 125 | 0 | 0 | 0 |
------------------------------------------------------------
Note that John has not made any calls in this date range, so his total CallCount is zero, but he is still in the list of results. I can't seem to figure out how to keep records like John's in the list. When I add the WHERE clause, those records are filtered out.
How can I create a select statement that displays all of the Employees and only SUMs/AVGs the values returned from the WHERE clause?

Use:
SELECT e.Name,
e.Extension,
Count(pc.*) AS CallCount,
AVG(pc.Duration) AS AverageCallTime,
SUM(pc.Duration) AS TotalCallTime
FROM Employees e
LEFT JOIN PhoneCalls pc ON pc.extension = e.extension
AND pc.StartTime BETWEEN "2010-09-12 09:30:00" AND NOW()
GROUP BY e.Name, e.Extension
The issue is when using an OUTER JOIN, specifying criteria in the JOIN section is applied before the JOIN takes place--like a derived table or inline view. The WHERE clause is applied after the OUTER JOIN, which is why when you specified the WHERE clause on the table being LEFT OUTER JOIN'd to that the rows you still wanted to see are being filtered out.