I am working on an assignment:
Compare the average daily revenue (as I define it in Teradata Week 5
Exercise Guide) of the store with the highest msa_income and the store
with the lowest median msa_income (according to the msa_income field).
In what city and state were these two stores, and which store had a
higher average daily revenue?
... and the answer key has a inner join in ON statement, which confused me a lot. I have only learnt Join in FROM. So I searched online about an inner join in ON statement, there was not much about it.
I am a new learner, so this question might be really basic. Thanks in advance for your patience!
The line I where I had a problem is: ON m.store=t.store JOIN strinfo s
SELECT SUM(store_rev. tot_sales)
SUM(store_rev.numdays) AS daily_average,
store_rev.msa_income as med_income,
store_rev.city, store_rev.state
FROM (SELECT COUNT (DISTINCT t.saledate) as numdays,
EXTRACT(YEAR from t.saledate) as s_year,
EXTRACT(MONTH from t.saledate) as s_month, t.store,
sum(t.amt) as tot_sales,
CASE
when extract(year from t.saledate) = 2005 AND extract(month from t.saledate) = 8 then 'exclude'
END as exclude_flag, m.msa_income, s.city, s.state
FROM trnsact t JOIN store_msa m
ON m.store=t.store JOIN strinfo s
ON t.store=s.store
WHERE t.stype = 'P' AND exclude_flag IS NULL
GROUP BY s_year, s_month, t.store, m.msa_income, s.city, s.state
HAVING numdays >= 20) as store_rev
WHERE store_rev.msa_income IN ((SELECT MAX(msa_income)
FROM store_msa),(SELECT MIN(msa_income) FROM store_msa))
GROUP BY med_income, store_rev.city, store_rev.state;
Perhaps it would be easier to follow if written like this:
FROM trnsact t JOIN
store_msa m
ON m.store = t.store JOIN
strinfo s
ON t.store = s.store
The JOIN isn't in the ON statement. The FROM clause consists of multiple joins, chained together.
You can think of the JOIN keyword as ending the ON clause and starting a new join condition.
Related
I have one table (city_data) with the columns 'year', 'city_name' and 'avg_temp'. The other table is global_data and has the columns 'avg_temp' and 'year'. I am trying to create a table which has the average temperature of London, the global average temperature for all the years.
My SQL code is the following:
SELECT city_data.avg_temp, city_data.year
FROM city_data
JOIN global_data
ON city_data.year = global_data.avg_temp
WHERE city= 'Paris'
I get no error but cannot get the expected result. I think I am not able to understand what I need to put in the ON clause.
I suppose that the table global_data has one row per year, while city_data has one row per year and city. This means you can simply join the two on the year they have in common:
select year, g.avg_temp as global_average, c.avg_temp as paris_average
from global_data g
join city_data c using (year)
where c.city = 'Paris'
order by year;
If you don't like to join the two and only then mention Paris, you can also turn this into:
select year, g.avg_temp as global_average, p.avg_temp as paris_average
from global_data g
join (select * from city_data where city = 'Paris') p using (year)
order by year;
As of MySQL 8 you can even use a WITH clause to "prepare" Paris :-)
with paris as (select * from city_data where city = 'Paris')
select year, g.avg_temp as global_average, paris.avg_temp as paris_average
from global_data g
join paris using (year)
order by year;
Or consider Paris a join criteria:
select g.year, g.avg_temp as global_average, p.avg_temp as paris_average
from global_data g
join city_data p on p.year = g.year and p.city = 'Paris'
order by g.year;
As you see, there are many ways to write the same query and the DBMS would probably come up with the same execution plan for all. So, just pick the query you like best.
This is completely based on the partial understanding
SELECT city_name, AVG(city_data.avg_temp) as global_avg
FROM
city_data
JOIN global_data
ON city_data.year = global_data.year
WHERE city_name = 'Paris'
GROUP BY city_data.city_name
FROM city_data
JOIN global_data
ON city_data.year = global_data.year
-- it should be global_data.year in Join
WHERE city= 'Paris'
As year is the only common attribute, join using it. Then fetch the city average table as it is readily availble in the city_data. Lastly do the avg for global_data, as you want to fetch it across years.
SELECT `city_name`, `city_data`.`avg_temp` AS city_avg_temp, AVG(`global_data`.`avg_temp`) AS global_avg_temp
FROM `city_data`
JOIN `global_data`
ON `city_data`.`year` = `global_data`.`year`
WHERE `city_name` = 'London'
GROUP BY `city_data`.`city_name`
I have 2 tables which I want to join and retrieve some specific data. These are my tables.
tbl_user (reg_id, l_name, f_name, status)
tbl_payments (pay_id, reg_id, mem_plan, from_date, to_date, bill_no, payed_date)
What I need to do is select and view the users who have due payments. To do that I want to get the user details where "status=0" from tbl_user and join the 2 tables together and the conditions are to_date< current date, difference between [current date and the to_date] < 31 and filter by the Max value of to_date.
What I did so far gives me a result according to above mentioned conditions except it dosen't filter by the MAX(to_date). This is my query.
SELECT
A.reg_id,
A.f_name,
A.l_name,
B.mem_plan,
B.from_date,
Max(B.to_date) AS to_date,
B.bill_no,
B.payed_date
FROM
tbl_user A,
tbl_payments B
WHERE
A.status = 0
AND A.reg_id = B.reg_id
AND Date(Now()) >= Date(B.to_date)
AND Datediff(Date(Now()), Date(b.to_date)) < 31
GROUP BY
a.reg_id, b.mem_plan, b.from_date, b.bill_no, b.payed_date;
I'm not very familiar with MYSQL, So please someone tell me what I did wrong or if this query is not up to the standard.
Here are some sample data to work on.
tbl_user ( [M1111,Jon, Doe,0], [M1112,Jane,Doe,1],[M1113,Jony,Doe,0] )
tbl_payment ( [1,M1111,Monthly,2018-05-14,2018-06-14,b123,2018-05-14],[2,M1112,3Months,2018-02-03,2018-05-03,b112,2018-02-03],[3,M1113,Monthly,2018-06-14,2018-07-14,b158,2018-06-14],[4,M1111,Monthly,2018-06-15,2018-07-15,b345,2018-06-15],[5,M1113,Monthly,2018-06-06,2018-07-06,b158,2018-06-06],[6,M1111,Monthly,2018-07-05,2018-08-05,b345,2018-07-05] )
Assuming current date is 2018-07-17, The expecting result should be this
[M1111,Jon,Doe,Monthly,2018-06-15,2018-07-15,b345,2018-06-15],[M1113,Jony,Doe,Monthly,2018-06-14,2018-07-14,b158,2018-06-14]
Instead of that, my query gives me this.
[M1111,Jon,Doe,Monthly,2018-06-15,2018-07-15,b345,2018-06-15],[M1113,Jony,Doe,Monthly,2018-06-06,2018-07-06,b158,2018-06-06],
[M1113,Jony,Doe,Monthly,2018-06-14,2018-07-14,b158,2018-06-14]
I wrote another query which gives me the result set exactly as i want. But I'm not sure whether it's up to the standards. If someone can simplify this or make it better, appreciate very much.
SELECT A.reg_id,A.f_name,A.l_name,D.mem_plan,D.from_date,D.to_date,D.bill_no,D.payed_date
FROM tbl_user A
JOIN (SELECT B.reg_id,B.mem_plan,B.from_date,B.to_date,B.bill_no,B.payed_date
FROM tbl_payments B
JOIN (
SELECT reg_id, MAX(to_date) as to_date
FROM tbl_payments
WHERE DATE(NOW()) >= DATE(to_date) AND DATEDIFF(DATE(NOW()), DATE(to_date))<31
GROUP BY reg_id) C
ON B.reg_id = C.reg_id AND B.to_date= C.to_date) D
ON A.reg_id = D.reg_id
WHERE A.status=0;
I believe having won't work here and that your second query is about as good as it gets. I've condensed it a little here:
SELECT A.reg_id,f_name,l_name,mem_plan,from_date,to_date,bill_no,payed_date
FROM #tbl_user A
JOIN #tbl_payments B ON A.reg_id = b.reg_id
JOIN (
SELECT reg_id, MAX(to_date) as max_to_date
FROM #tbl_payments
WHERE DATE(NOW()) >= DATE(to_date) AND DATEDIFF(DATE(NOW()), DATE(to_date))<31
GROUP BY reg_id
) C ON B.reg_id = C.reg_id AND B.to_date= C.max_to_date
WHERE A.status=0;
I have written an sql statement that besides all the other columns should return the number of comments and the number of likes of a certain post. It works perfectly when I don't try to get the number of times it has been shared too. When I try to get the number of time it was shared instead it returns a wrong number of like that seems to be either the number of shares and likes or something like that. Here is the code:
SELECT
[...],
count(CS.commentId) as shares,
count(CL.commentId) as numberOfLikes
FROM
(SELECT *
FROM accountSpecifics
WHERE institutionId= '{$keyword['id']}') `AS`
INNER JOIN
account A ON A.id = `AS`.accountId
INNER JOIN
comment C ON C.accountId = A.id
LEFT JOIN
commentLikes CL ON C.commentId = CL.commentId
LEFT JOIN
commentShares CS ON C.commentId = CS.commentId
GROUP BY
C.time
ORDER BY
year, month, hour, month
Could you also tell me if you think this is an efficient SQL statement or if you would do it differently? thank you!
Do this instead:
SELECT
[...],
(select count(*) from commentLikes CL where C.commentId = CL.commentId) as shares,
(select count(*) from commentShares CS where C.commentId = CS.commentId) as numberOfLikes
FROM
(SELECT *
FROM accountSpecifics
WHERE institutionId= '{$keyword['id']}') `AS`
INNER JOIN account A ON A.id = `AS`.accountId
INNER JOIN comment C ON C.accountId = A.id
GROUP BY C.time
ORDER BY year, month, hour, month
If you use JOINs, you're getting back one result set, and COUNT(any field) simply counts the rows and will always compute the same thing, and in this case the wrong thing. Subqueries are what you need here. Good luck!
EDIT: as posted below, count(distinct something) can also work, but it's making the database do more work than necessary for the answer you want to end up with.
Quick fix:
SELECT
[...],
count(DISTINCT CS.commentId) as shares,
count(DISTINCT CL.commentId) as numberOfLikes
Better approach:
SELECT [...]
, Coalesce(shares.numberOfShares, 0) As numberOfShares
, Coalesce(likes.numberOfLikes , 0) As numberOfLikes
FROM [...]
LEFT
JOIN (
SELECT commentId
, Count(*) As numberOfShares
FROM commentShares
GROUP
BY commentId
) As shares
ON shares.commentId = c.commentId
LEFT
JOIN (
SELECT commentId
, Count(*) As numberOfLikes
FROM commentLikes
GROUP
BY commentId
) As likes
ON likes.commentId = c.commentId
I am having trouble getting a MySQL query to work for me. Here is the setup.
A customer has asked me to compile a report from some accounting data. He wants to select a date (and possibly other criteria) and have it return all of the following (an OR statement):
1.) All invoices that were inserted on or after that date
2.) All invoices regardless of their insert date that have corresponding payments in a separate table whose insert dates are on or after the selected date.
The first clause is basic, but I am having trouble pairing it with the second.
I have assembled a comparable set of test data in an SQL Fiddle. The query that I currently have is provided.
http://www.sqlfiddle.com/#!2/d8d9c/3/2
As noted in the comments of the fiddle, I am working with July 1, 2013 as my selected date. For the test to work, I need invoices 1 through 5 to appear, but not invoice #6.
Try this: http://www.sqlfiddle.com/#!2/d8d9c/9
Here are the summarized changes
I got rid of your GROUP BY. You did not have any aggregate functions. I used DISTINCT instead to eliminate duplicate records
I removed your implicit joins and put explicit joins in their place for readability. Then I changed them to LEFT JOINs. I am not sure what your data looks like but at a minimum, I would assume you need the payments LEFT JOINed if you want to select an invoice that has no payments.
This will probably get you the records you want, but those subselects in the SELECT clause may perform better as LEFT JOINs then using the SUM function
Here is the query
SELECT DISTINCT
a.abbr landowner,
CONCAT(f.ForestLabel, '-', l.serial, '-', l.revision) leasenumber,
i.iid,
FROM_UNIXTIME(i.dateadded,'%M %d, %Y') InvoiceDate,
(SELECT IFNULL(SUM(ch.amount), 0.00) n FROM test_charges ch WHERE ch.invoiceid = i.iid) totalBilled,
(SELECT SUM(p1.amount) n FROM test_payments p1 WHERE p1.invoiceid = i.iid AND p1.transtype = 'check' AND p1.status = 2) checks,
(SELECT SUM(p1.amount) n FROM test_payments p1 WHERE p1.invoiceid = i.iid AND p1.transtype = 'ach' AND p1.status = 2) ach,
CASE WHEN i.totalbilled < 0 THEN i.totalbilled * -1 ELSE 0.00 END credits,
CASE WHEN i.balance >= 0 THEN i.balance ELSE 0.00 END balance,
t.typelabel, g.groupname
FROM test_invoices i
LEFT JOIN test_contracts c
ON i.contractid = c.cid
LEFT JOIN test_leases l
ON c.leaseid = l.bid
LEFT JOIN test_forest f
ON l.forest = f.ForestID
LEFT JOIN test_leasetypes t
ON l.leasetype = t.tid
LEFT JOIN test_accounts a
ON l.account = a.aid
LEFT JOIN test_groups g
ON c.groupid = g.gid
LEFT JOIN test_payments p
ON p.invoiceid = i.iid
WHERE (i.dateadded >= #startdate) OR (p.dateadded >= #startdate)
Try this.
http://www.sqlfiddle.com/#!2/d8d9c/11/2
TL;DR:
… AND (i.dateadded > #startdate
OR EXISTS (
SELECT * FROM test_payments
WHERE test_payments.invoiceid = i.iid
AND test_payments.dateadded >= #startdate))
I have the following that returns the total invoiced amount for a given type of job. I now want to break it down into monthly totals. Any tips on how I should approach this
SELECT dbo.jm_job_type.job_type_desc, SUM(dbo.jm_invoice.invoice_amount) AS 'inv tot'
FROM dbo.jm_invoice INNER JOIN
dbo.jm_job ON dbo.jm_invoice.job_no = dbo.jm_job.job_no INNER JOIN
dbo.jm_job_type ON dbo.jm_job.job_type_no = dbo.jm_job_type.job_type_no
GROUP BY dbo.jm_job_type.job_type_desc
"floor" to the Month (most efficient way to get month+year only) and then GROUP BY that"
GROUP BY DATEADD(month,DATEDIFF(month,0, dbo.jm_invoice.YourDate),0)
so it would be:
SELECT dbo.jm_job_type.job_type_desc,
DATEADD(month,DATEDIFF(month,0, dbo.jm_invoice.YourDate),0) AS MonthYear,
SUM(dbo.jm_invoice.invoice_amount) AS 'inv tot'
FROM dbo.jm_invoice INNER JOIN
dbo.jm_job ON dbo.jm_invoice.job_no = dbo.jm_job.job_no INNER JOIN
dbo.jm_job_type ON dbo.jm_job.job_type_no = dbo.jm_job_type.job_type_no
GROUP BY dbo.jm_job_type.job_type_desc,
DATEADD(month,DATEDIFF(month,0, dbo.jm_invoice.YourDate),0)
Use the SQL Server datepart function on the date in question in your Group By like this:
GROUP BY
DatePart(yy, dbo.jm_invoice.some_date),
DatePart(mm, dbo.jm_invoice.some_date),
dbo.jm_job_type.job_type_desc
Add the year and month field to your SELECT list, and also add it to your GROUP BY list