Am trying to use left join to get previous school term fee balances as fee arrears for the current term. I already have a query displaying current fee balances. Am using the SQL below, I know am on the right track, please help.
SELECT Q1.pYear, Q1.term, Q2.Feedue As Arrears
FROM qryfeebalances AS Q1 LEFT JOIN qryfeebalances AS Q2 ON Q1.pyear & Q1.Term>Q2.pyear & Q2.term
GROUP BY Q1.pYear, Q1.Term, Q1.Strstudentid, Q1.Class;
I got it, thought I should post so that someone may use it later.
SELECT Q1.pYear, Q1.term, Sum([Q2.Feedue]) As Arrears
FROM qryfeebalances AS Q1 LEFT JOIN qryfeebalances AS Q2 ON Q1.pyear & Q1.Term>Q2.pyear & Q2.term And Q1.strstudentid=Q2.strstudentid
GROUP BY Q1.pYear, Q1.Term, Q1.Strstudentid, Q1.Class;
Related
I have two tables, one that lists grants/loans and one that lists individual expenditures. They share an ID column as each expenditure is assigned to a specific grant or loan. I'm trying to use LEFT JOIN to sum the expenditures for all the loans combined, but not the grants.
Here's where I'm at:
SELECT SUM(expenses.total_amt) AS total
FROM expenses WHERE loans_grants.grant_loan_type = 'Loan'
LEFT JOIN loans_grants
ON expenses.grant_loan_id = loans_grants.internal_id;
Any tips much appreciated!
Edit: thanks all, and apologies for the half baked question, it was late and I was in the weeds.
Here's the basic structures:
expenses:
expenses table structure
loans_grants:
loans_grants table structure
I've updated the code based on #jwood74's answer to this:
SELECT l.internal_id, SUM(e.total_amt) amount
FROM loans_grants l
LEFT JOIN expenses e ON e.grant_loan_id = l.internal_id
WHERE grant_loan_type = 'Loan'
group by l.internal_id
which produces this:
internal id
amount
1
3234
4
null
5
7625
7
null
9
null
Please excuse my noviceness, but I'm trying to sum up all expenses for loans, so I'd like to return 3234 + 7625, rather than summing expenses for each loan separately. Thanks for your help!
If you are looking for a SINGLE ROW RETURNED, you do not need to do a group by anything... just the SUM() of what you are looking for.
Second, do not post pictures of your sample data and table structures. Edit your original post and type the values in, even if you copy/paste the data and format it for readability (via Ctrl+K, or the curly brackets {} icon above post editing header area).
In this case, your tables
Loan_Grants table
Internal_id grant_loan_type
1 Loan
2 Grant
3 Grant
4 Loan
5 Loan
6 Grant
7 Loan
8 Grant
9 Loan
Expenses Table
total_amt grant_loan_id
2000 1
245 5
4500 5
2200 5
445 5
185 5
1234 1
50 5
Starting with your Loan_Grants table filtered on just your 'Loan' records
select
sum( e.total_amt ) totalExpenses
from
loan_grants lg
JOIN expenses e
on lg.internal_id = e.grant_loan_id
where
lg.grant_loan_type = 'Loan'
You dont want a left-join unless you explicitly want to see ALL "Loan" entries, even if they have no expenses yet recorded. By doing a regular (inner) JOIN, it means there MUST be a record in the expenses table. Again, based on your needs. If you have 10,000 loans and only 247 loans have expenses, do you want to see all 10,000 or just the 247 and what their totals are. Since you are summarizing to a single return record, JOIN is your best choice here.
For future, ALWAYS try to apply a table.column or alias.column to all your fields so anyone assisting does not have to guess which table the column comes from.
Without knowing the exact format of the two tables, it's a bit hard. But here would be the general idea-
select
l.id,
sum(e.amount) amount
from loans_grants l
left join expenses e on e.grant_loan_id = l.internal_id
where grant_loan_type = 'Loan'
group by l.id
I'm trying to figure out this task, but after trying and trying i am not able to solve it. Can someone with more SQL experience help me out?
I have 3 tables:
[
The task is to calculate the average age (alter) from each person who visited a restaurant located in Salzburg. If a person visited a restaurant that is located in Salzburg twice, it should be added to the average age (Emily in this case).
Since Piccolo and Stella are located in Salzburg, 4 visits happen overall.
But how do i pull this off in SQL?
How do i count the visits?
Any help is appreciated. Thanks in advance everyone!
MySQL Version: 8.0.20
Using MySQL Workbench.
EDIT 4:
Was able to find the solution on my own more or less, although the answer from #Nick is awesome as well, which is why i accept his answer as correct.
Thank you all so much and #Nick!
Just in case someone runs into the same issue,
my final solution is:
SELECT (AVG(age)) FROM PERSON INNER JOIN ISST ON PERSON.person_name = ISST.person_name INNER JOIN PIZZERIA ON ISST.pizzeria_name = PIZZERIA.pizzeria_name && PIZZERIA.stadt="Salzburg";
Since you want to calculate the average age of all visitors (regardless of whether a person visits a pizzeria in the same city twice), you can just JOIN your visits table to the pizzeria and person tables and average the results:
SELECT AVG(p.alter)
FROM ISST i
JOIN PIZZERIA z ON z.pizzeria_name = i.pizzeria_name
JOIN PERSON p ON p.person_name = i.person_name
WHERE z.stadt = 'Salzburg'
Output:
25.75
Demo on dbfiddle
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I have a sales table, a sale_staff table, a staff table and an offices table.
We are selling properties, and I want to find out the numbers of sales per seller for X month and per office.
The pivot table looks like this
sale_id , staff_id , type
type can be either seller or lister, so I need a where clause for this.
The sales table has a FK to the offices table; office_id
What I have so far is this, its TOTALLY wrong I know, but that's why i'm here - i need to fix the sums and include the office name from the office table, so
select st.first_name, st.last_name, office, count(*) as sold
from sales s, sale_staff ss
left join staff st
on st.id = ss.staff_id
left join offices off
on off.id = s.office_id
where ss.`type` = 'lister' and
year(s.sale_date) = 2017 and
month(s.sale_date) = 12
group by st.id
Sales table is simply a property sale item, price, address, office_id.
Besides the error unknown column s.office_id, as I said, the sum value is incorrect anyway. I'm really not experienced enough to understand this level of relationship joins and aggregating, any pointers please.
Basically I would like to simply see a resultset like
staff(seller) , count , office
Mike , 12 , West
Jim , 7 , East
Fred , 3 , East
Edit: SQLFiddle in case that helps :) Will add some sample test data.
Never use commas in the FROM clause. Always use proper, explicit JOIN syntax. Your problem is because of the scoping rules around commas.
I would recommend:
select st.first_name, st.last_name, o.office, count(*) as sold
from staff st left join
sale_staff ss
on st.id = ss.staff_id join
sales sa
on sa.sale_id = ss.sale_id join
offices o
on o.id = s.office_id
where ss.`type` = 'lister' and
s.sale_date >= '2017-12-01' and
s.sale_date < '2018-01-01'
group by st.first_name, st.last_name, o.office;
I think this has the join condition correctly laid out, but it is hard to be sure without sample data and desired results.
Notes:
left join is probably not necessary. If it is, you should probably be starting with the staff table (to keep all staff).
Qualify all column names.
The group by includes all the non-aggregated columns in the from. This is a good habit if you are learning SQL.
The date comparisons are direct, without the use of functions.
I have a practice problem where I am to write a query to find the top most 15 percent profitable products in the year 2005 from a database. The database does NOT have attributes like "Saleprice, or Purchaseprice". It has tables like PUrchaseProductDetails or SalesOrderDetails, and other stuff with Unitprice, orderquantity, ProdID, LIstPrice, ActualCost, StandardPrice, etc as attributes. I am confused as to which one I should use and how to come up with a formula. I tried to write a query, but got infinitely running results.
SELECT A.ProdID, B.ProdID, A.Unitprice - (B.Unitprice * orderquantity) Profit
FROM SalesOrderDetails A join PurchaseOrderD B
ON A.ProdID = B.ProdID
WHERE year(DateOrdered) = 2005
Group by A.ProdID
I have spent hours on these type of questions and my brain is at a dead end right now. If someone can please direct me to do it the right way, it would really help me out.
SELECT sale.ProdID, sum(sale.Unitprice - buy.Unitprice) * sale.Qty AS profit
FROM SalesOrderDetails AS sale
JOIN PurchaseOrderD AS buy ON ...
WHERE year(...) = 2005
GROUP BY 1
ORDER BY 2 DESC
LIMIT 15
I have been playing around with this for what seems like hours and I can't get the results I want. Here is the query I am having trouble with:
SELECT year.year, dstate,
(SELECT sum(amount) FROM gift
WHERE year.year = gift.year
AND gift.donorno = donor.donorno)
FROM donor, gift, year
WHERE year.year = gift.year
AND gift.donorno = donor.donorno;
This seems redundant. Anyway, I am trying display the total donations (gift.amount) for each state by year.
ex.
1999 GA 500 (donorno 1 from GA donated 200 and donorno 2 from GA donated 300)
1999 FL 400
2000 GA 600
2000 FL 500
...
To clarify donors can be from the same state but I am trying to total the gift amounts for that state for the year it is donated.
Any advice is appreciated. I feel like the answer is right in front of me.
Here is a picture of tables for reference:
This is a very simple join & aggregation problem.
SELECT y.year, d.state, SUM(g.amount) AS total
FROM gift AS g
INNER JOIN year AS y ON y.year=g.year
INNER JOIN donor AS d ON d.donorno=g.donorno
GROUP BY y.year, d.state
You don't need the sub-query in your SELECT clause in order to get the total amount. You can sum it by grouping. (I think the GROUP BY clause is what you're missing. I recommend reading up on it.) What you've done is called a correlated sub-query and it is going to be very slow over large data sets because it has to be calculated row-by-row instead of as a set operation.
Also, please don't use the old style comma join syntax. Instead use the explicit join syntax as shown above. It is much clearer and will help avoid accidental Cartesian products.