I have 2 tables in Mysql. I want to regroup and count the Number of Orderid per month for each customer. If there is no order, I would like to add 0.
Customer Table
CustomerID
1
2
3
Order Table
OrderId CustomerID Date
1 1 2022-01-02
2 1 2022-01-04
3 2 2022-02-03
4 2 2022-03-03
Expect results
CustomerID Date CountOrderID
1 2022-01 2
2 2022-01 1
3 2022-01 0
1 2022-02 0
2 2022-02 1
3 2022-02 0
1 2022-03 0
2 2022-03 1
3 2022-03 0
How I can do this in Mysql?
SELECT customer.CustomerID,
year_month.y_m AS `Date`,
COUNT(order.OrderId) AS CountOrderID
FROM customer
CROSS JOIN (
SELECT DISTINCT DATE_FORMAT(`date`, '%Y-%m') AS y_m
FROM order
) AS year_month
LEFT JOIN order ON order.CustomerID = customer.CustomerID
AND DATE_FORMAT(order.`date`, '%Y-%m') = year_month.y_m
GROUP BY 1, 2;
If order table does not contains for some year and month then according row won't present in the output. If you need in it then you'd generate calendar table instead of year_month subquery.
you can reduce the number of cte's I added more here to explain the steps:
first you need the format year and month, for that I used DATE_FORMAT() function
since you need to have all the combination of dates and the year month you need a cross join. This will produce all the distinct dates with all the distinct customer id's. In other words all the pairs between dates and customer id
once you have a table with all the combinations you need to pass the actual data with the left join this will produce null where you actually don't have rows and hence will produce 0 when the count is performed
the last step is simply count function
with main as (
select distinct DATE_FORMAT(date,'%Y-%m') as year_month from order
),
calendar as (
select * from customer
cross join main
),
joining_all as (
select
calendar.*,
order. OrderId
left join order
on calendar.CustomerID = order.CustomerID
and calendar.year_month = DATE_FORMAT(order.date,'%Y-%m')
)
select
CustomerID,
year_month as Date,
count(OrderId) as CountOrderID
from joining_all
group by 1,2
maybe the shorter version can work with the code below. if runs into syntax you can use the one above
with main as (
select distinct DATE_FORMAT(date,'%Y-%m') as year_month from order
cross join customer
)
select
main.CustomerID,
main.year_month as Date,
count(order.OrderId) as CountOrderID
from main
left join order
on main.CustomerID = order.CustomerID
and main.year_month = DATE_FORMAT(order.date,'%Y-%m')
group by 1,2
i have an orders table, and i need to fetch the orders record by month. but i have terms if there is no data in a month it should still show the data but forcing to zero like this:
what i have done is using my query:
select sum(total) as total_orders, DATE_FORMAT(created_at, "%M") as date
from orders
where is_active = 1
AND tenant_id = 2
AND created_at like '%2021%'
group by DATE_FORMAT(created_at, "%m")
but the result is only fetched the existed data:
can anyone here help me to create the exactly query?
Thank you so much
Whenever you're trying to use a value that doesn't exist in the table, one option is to use a reference; whether it's from a table or a query-generated value.
I'm guessing that in terms of date data, the column created_at in table orders may have a complete list all the 12 months in a year regardless of which year.
Let's assume that the table data for orders spans from 2019 to present date. With that you can simply create a 12 months reference table for a LEFT JOIN operation. So:
SELECT MONTHNAME(created_at) mnt FROM orders GROUP BY MONTHNAME(created_at);
You can append that into your query like:
SELECT IFNULL(SUM(total),0) as total_orders, mnt
from (SELECT MONTHNAME(created_at) mnt FROM orders GROUP BY MONTHNAME(created_at)) mn
LEFT JOIN orders o
ON mn.mnt=MONTHNAME(created_at)
AND is_active = 1
AND tenant_id = 2
AND created_at like '%2021%'
GROUP BY mnt;
Apart from adding the 12 months sub-query and a LEFT JOIN, there are 3 other changes from your original query:
IFNULL() is added to the SUM() operation in SELECT to return 0 if the value is non-existent.
All the WHERE conditions has been switched to ON since remaining it as WHERE will make the LEFT JOIN becoming a normal JOIN.
GROUP BY is using the sub-query generated month (mnt) value instead.
Taking consideration of table orders might not have the full 12 months, you can generate it from query. There are a lot of ways of doing it but here I'm only going to show the UNION method that works with most MySQL version.
SELECT MONTHNAME(CONCAT_WS('-',YEAR(NOW()),mnt,'01')) dt
FROM
(SELECT 1 AS mnt UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION
SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION
SELECT 9 UNION SELECT 10 UNION SELECT 11 UNION SELECT 12) mn
If you're using MariaDB version that supports SEQUENCE ENGINE, the same query above is much shorter:
SELECT MONTHNAME(CONCAT_WS('-',YEAR(NOW()),mnt,'01'))
FROM (SELECT seq AS mnt FROM seq_1_to_12) mn
I'm using MariaDB 10.5 in this demo fiddle however it seems like the month name ordering is based on the name value rather than the month itself so it looks un-ordered. It's in the correct order if it's in MySQL 8.0 fiddle though.
Thanks all for the answers & comments i really appreciate it.
i solved it by create table helper for static months then use union and aliasing, since i need the months in indonesia, i create case-when function too.
so, the query is like this:
SELECT total_orders,
(CASE date WHEN 01 THEN 'Januari'
WHEN 02 THEN 'Februari'
WHEN 03 THEN 'Maret'
WHEN 04 THEN 'April'
WHEN 05 THEN 'Mei'
WHEN 06 THEN 'Juni'
WHEN 07 THEN 'Juli'
WHEN 08 THEN 'Agustus'
WHEN 09 THEN 'September'
WHEN 10 THEN 'Oktober'
WHEN 11 THEN 'November'
WHEN 12 THEN 'Desember'
ELSE date END ) AS date
FROM (SELECT SUM(total) AS total_orders,
DATE_FORMAT(created_at, "%m") AS date
FROM orders
WHERE is_active = 1
AND tenant_id = 2
AND created_at like '%2021%'
GROUP BY DATE_FORMAT(created_at, "%m")
UNION
SELECT 0 AS total_orders,
code AS date
FROM quantum_default_months ) as Q
GROUP BY date
I still don't know if this query is fully correct or not, but I get my exact result.
cmiiw.
thanks all
I need to combine these two queries and get records using the single mySQL query.
Here are my queries
select DATE_FORMAT(campaign_date, '%Y-%m' ) AS month
, sum(sms)
from table1
group
by month
it returns me, sum of all months e.g
2019-05 5400
2019-06 3200
2019-07 11505
etc
I have another query which gets data in same format but from a different table.
select DATE_FORMAT(trans_date, '%Y-%m' ) AS month
, sum(camp_sms)
from table2
group
by month
2019-05 3500
2019-06 7256
2019-07 35465
etc
is it possible to combine these two query and get data same like this below:
Date sum(sms) sum(camp_sms)
2019-05 5400 3500
2019-06 3200 7256
2019-07 11505 35465
I have done this using PHP loops & array and to get the same output, but i want to do it using mySQL.
Simply use join
select t1.month, t1.total, t2.total from (
select DATE_FORMAT(campaign_date, '%Y-%m' ) AS month, sum(sms) total from table1 group by month
) t1
join (
select DATE_FORMAT(trans_date, '%Y-%m' ) AS month, sum(camp_sms) from table2 group by month
) t2 on t1.month = t2.month
If you don't want to skip any data from table1, then you should LEFT JOIN similarly you can use other joins according to your requirements.
I have an elementary SQL query:
SELECT MONTH(created_at), COUNT(id) as total FROM `clients` GROUP BY MONTH(created_at)
It returns me data groupped by month like as:
MONTH(created_at) | total
09 1
10 2
How to fill remaining months to zero? So, in result I need to get all months:
MONTH(created_at) | total
09 1
.. 2
12 5
I tried this way:
SELECT months.id, COUNT(clients.id) as total FROM `months` LEFT JOIN `clients` ON MONTH(created_at) = months.id GROUP BY MONTH(created_at)
Use a derived table with all month numbers and left join your table on to that.
SELECT mths.mth, COUNT(c.id) as total
FROM (select 1 as mth union select 2 union select 3 union
select 4 union select 5 union select 6 union select 7 union
select 8 union select 9 union select 10 union select 11 union select 12) mths
LEFT JOIN `clients` c on mths.mth=month(c.created_at)
GROUP BY mths.mth
The best practice is to have CALENDAR table, from which you can query period you need and then left join table with data.
Or you can simply generate list of periods you need. In case you have a small period, you can use derived table. The fastest way in this case would be excel-generated list.
Thank all for answers, especially Alex, this way works:
SELECT months.id, COUNT(clients.id) as total FROM `months` LEFT JOIN `clients` ON months.id = MONTH(created_at) GROUP BY months.id;
I am storing hourly results in a MySQL database table which take the form:
ResultId,CreatedDateTime,Keyword,Frequency,PositiveResult,NegativeResult
349,2015-07-17 00:00:00,Homer Simpson,0.0,0.0,0.0
349,2015-07-17 01:00:00,Homer Simpson,3.0,4.0,-2.0
349,2015-07-17 01:00:00,Homer Simpson,1.0,1.0,-1.0
349,2015-07-17 04:00:00,Homer Simpson,1.0,1.0,0.0
349,2015-07-17 05:00:00,Homer Simpson,8.0,3.0,-2.0
349,2015-07-17 05:00:00,Homer Simpson,1.0,0.0,0.0
Where there might be several results for a given hour, but none for certain hours.
If I want to produce averages of the hourly results, I can do something like this:
SELECT ItemCreatedDateTime AS 'Created on',
KeywordText AS 'Keyword', ROUND(AVG(KeywordFrequency), 2) AS 'Average frequency',
ROUND(AVG(PositiveResult), 2) AS 'Average positive result',
ROUND(AVG(NegativeResult), 2) AS 'Average negative result'
FROM Results
WHERE ResultsNo = 349 AND CreatedDateTime BETWEEN '2015-07-13 00:00:00' AND '2015-07-19 23:59:00'
GROUP BY KeywordText, CreatedDateTime
ORDER BY KeywordText, CreatedDateTime
However, the results only include the hours where data exists, e.g.:
349,2015-07-17 01:00:00,Homer Simpson,2.0,2.5,-1.5
349,2015-07-17 04:00:00,Homer Simpson,1.0,1.0,0.0
349,2015-07-17 05:00:00,Homer Simpson,4.5,1.5,-1.0
But I need to show blanks rows for the missing hours, e.g.
349,2015-07-17 01:00:00,Homer Simpson,2.0,2.5,-1.5
349,2015-07-17 02:00:00,Homer Simpson,0.0,0.0,0.0
349,2015-07-17 03:00:00,Homer Simpson,0.0,0.0,0.0
349,2015-07-17 04:00:00,Homer Simpson,1.0,1.0,0.0
349,2015-07-17 05:00:00,Homer Simpson,4.5,1.5,-1.0
Short of inserting blanks into the results before they are presented, I am uncertain of how to proceed: can I use MySQL to include the blank rows at all?
SQL in general has no knowledge about the data, so you have to add that yourself. In this case you will have to insert the not used hours somehow. This can be done by inserting empty rows, or a bit different by counting the hours and adjusting your average for that.
Counting the hours and adjusting the average:
Count all hours with data (A)
Calculate the number of hours in the period (B)
Calculate the avg as you already did, multiply by A divide by B
Example code to get the hours:
SELECT COUNT(*) AS number_of_records_with_data,
(TO_SECONDS('2015-07-19 23:59:00')-TO_SECONDS('2015-07-13 00:00:00'))/3600
AS number_of_hours_in_interval
FROM Results
WHERE ResultsNo = 349 AND CreatedDateTime
BETWEEN '2015-07-13 00:00:00' AND '2015-07-19 23:59:00'
GROUP BY KeywordText, CreatedDateTime;
And just integrate it with the rest of your query.
You can't use MySQL for that. You'll have to do this with whatever you're using later to process the results. Iterate over the range of hours/dates you're interested in and for those, where MySQL returned some data, us that data. For the rest, just add null/zero values.
Small update after some discussions with my stackoverflow colleagues:
Instead of you can't I should have wrote you shouldn't - as other users have proved there are ways to do this. But I still believe that for different tasks we should use tools that were created having such tasks in mind. And by that I mean that while it's probably possible to tow a car with an F-16, it's still better to just call a tow truck ;) That's what tow trucks are made for.
Although you already have accepted an answer I want to demonstrate how you can generate a datetime series in the query and use that to solve your problem.
This query uses a combination of cross joins together with basic arithmetic and date functions to generate a series of all hours between 2015-07-16 00:00:00 AND 2015-07-18 23:59:00.
Generating this type of data on the fly isn't the best option though; if you already had a table with the numbers 0-31 then all the union queries would be unnecessary.
See this SQL Fiddle to see how it could look using a small number table.
Sample SQL Fiddle with a demo of the query below
select
c.createddate as "Created on",
c.Keyword,
coalesce(ROUND(AVG(KeywordFrequency), 2),0.0) AS 'Average frequency',
coalesce(ROUND(AVG(PositiveResult), 2),0.0) AS 'Average positive result',
coalesce(ROUND(AVG(NegativeResult), 2),0.0) AS 'Average negative result'
from (
select
q.createddate + interval d day + interval t hour as createddate,
d.KeywordText AS 'Keyword'
from (
select distinct h10*10+h1 d from (
select 0 as h10
union all select 1 union all select 2 union all select 3
) d10 cross join (
select 0 as h1
union all select 1 union all select 2 union all select 3
union all select 4 union all select 5 union all select 6
union all select 7 union all select 8 union all select 9
) d1
) days cross join (
select distinct t10*10 + t1 t from (
select 0 as t10 union all select 1 union all select 2
) h10 cross join (
select 0 as t1
union all select 1 union all select 2 union all select 3
union all select 4 union all select 5 union all select 6
union all select 7 union all select 8 union all select 9
) h1
) hours
cross join
-- use the following line to set the start date for the series
(select '2015-07-16 00:00:00' createddate) q
-- or use the line below to use the dates in the table
-- (select distinct cast(CreatedDateTime as date) CreatedDate from results) q
cross join (select distinct KeywordText from results) d
) c
left join results r on r.CreatedDateTime = c.createddate AND ResultsNo = 349 and r.KeywordText = c.Keyword
where c.createddate BETWEEN '2015-07-16 00:00:00' AND '2015-07-18 23:59:00'
GROUP BY c.createddate, Keyword
ORDER BY c.createddate, Keyword;
I came up with an idea to do it for add rows with null values in the last of your MySQL query.
Just run this query (in the limit add any number of empty rows you want), and ignore the last column:
SELECT ItemCreatedDateTime AS 'Created on',
KeywordText AS 'Keyword',
ROUND(AVG(KeywordFrequency), 2) AS 'Average frequency',
ROUND(AVG(PositiveResult), 2) AS 'Average positive result',
ROUND(AVG(NegativeResult), 2) AS 'Average negative result',
null
FROM Results
WHERE ResultsNo = 349 AND CreatedDateTime BETWEEN '2015-07-13 00:00:00' AND
'2015-07-19 23:59:00'
GROUP BY KeywordText, CreatedDateTime
UNION
SELECT * FROM (
SELECT null a, null b, null c, null d, null e,
(#cnt := #cnt + 1) f
FROM (SELECT null FROM Results LIMIT 23) empty1
LEFT JOIN (SELECT * FROM Results LIMIT 23) empty2 ON FALSE
JOIN (SELECT #cnt := 0) empty3
) empty
ORDER BY KeywordText, CreatedDateTime