Can I include an additional counter in a MySQL result set? I have the following query which gives me two columns back. I need an additional column (only in the result) indicating the row of each line in the result set.
select orderid, round(sum(unitprice * quantity),2) as value
from order_details
group by orderid
order by 2 desc
limit 10
I need something like the following:
10865 1 17250.00
11030 2 16321.90
10981 3 15810.00
10372 4 12281.20
10424 5 11493.20
Try this:
SET #counter = 0;
Select sub.*
FROM
(
select orderid, (#counter := #counter +1) as counter,
round(sum(unitprice * quantity),2) as value
from order_details
group by orderid
) sub
order by 2 desc
Try following
SET #counter = 0;
select orderid, (#counter:= #counter + 1) as counter, round(sum(unitprice * quantity),2) as value
from order_details
group by orderid
order by 3 desc
limit 10
Hope it helps...
Based on the two answers I managed to get the following:
SET #counter = 0;
Select sub.orderid,sub.value,(#counter := #counter +1) as counter
FROM
(
select orderid,
round(sum(unitprice * quantity),2) as value
from order_details
group by orderid
) sub
order by 2 desc
limit 10
The original answers showed the IDs from the inner query resulting in larger ints with huge gaps. Using the modification I get just the '1 to x' range that I need for my pgfplots LaTeX plot.
Related
I have a table in MySQL (phpMYAdmin) with the following columns
I am trying to determine the percentile for each row and update that value in the G1Ptile column. G1Ptile column is the percentile calculation based on G1%. I am using the following based on John Woo's answer given here
SELECT `G1%`,
(1-ranks/totals)*100 Percentile FROM (
SELECT distinct `G1%`,
#rank:=#rank + 1 ranks,
(SELECT COUNT(*) FROM PCount) totals
FROM PCount a,
(SELECT #rank:=0) s
ORDER BY `G1%` DESC ) s;
and get the following output
The output is in a select statement, I want to be able to update it to the G1Ptile column in my table, however I am unable to update it using
UPDATE `PCount` SET `G1Ptile`= --(All of the select query mentioned above)
Can you please help with modifying the query/suggest an alternative so that I can use the percentile values obtained using the above query and update it into G1Ptile in the same table. One more problem I have is that there are two 20% values in G1%, however the percentile assigned to one is 20 and other is 30. I want both of them to be 20 and the next row in the series to be 30.
I would write your calculation as:
SELECT `G1%`,
(1 - ranks / totals) * 100 as Percentile
FROM (SELECT `G1%`,
(#rank := #rank + 1) ranks,
(SELECT COUNT(*) FROM PCount) as totals
FROM (SELECT DISTINCT `G1%`
FROM PCount
ORDER BY `G1%` DESC
) p CROSS JOIN
(SELECT COUNT(*) as totals, #rank := 0
FROM Pcount
) params
) p;
I made certain changes more consistent with how MySQL processes variables. In particular, the SELECT DISTINCT and ORDER BY are in a subquery. This is necessary in more recent versions of MySQL (although in the most recent you can use window functions).
This can now be incorporated into an update using JOIN:
UPDATE PCount p JOIN
(SELECT `G1%`,
(1 - ranks / totals) * 100 as Percentile
FROM (SELECT `G1%`,
(#rank := #rank + 1) ranks,
(SELECT COUNT(*) FROM PCount) as totals
FROM (SELECT DISTINCT `G1%`
FROM PCount
ORDER BY `G1%` DESC
) p CROSS JOIN
(SELECT COUNT(*) as totals, #rank := 0
FROM Pcount
) params
) pp
) pp
ON pp.`G1%` = p.`G1%`
SET p.G1Ptile = pp.percentile;
I have a table like this:
01-Jul-17 100
02-Jul-17 100
03-Jul-17 300
04-Jul-17 300
05-Jul-17 500
06-Jul-17 500
07-Jul-17 300
08-Jul-17 400
09-Jul-17 100
10-Jul-17 100
What I want to output is (in this order) by eliminating the continuous duplicates but not all duplicates:
100
300
500
300
400
100
I cannot select Distinct, as it will eliminate the second instances of 300, 100. Is there a way to achieve this result in MySQL?
Thanks!
You want to get the previous value. If the dates really have no gaps or duplicates, just do:
select t.*
from t left join
t tprev
on t.col1 = date_add(tprev.col1, interval 1 day)
where tprev.col2 is null or tprev.col2 <> t.col2;
EDIT:
If the dates don't meet these conditions, then you can use variables:
select t.*
from (select t.*,
(#rn := if(#v = col2, #rn + 1,
if(#v := col2, 1, 1)
)
) as rn
from t cross join
(select #v := 0, #rn := 0) params
order by t.col1
) t
where rn = 1;
Note that MySQL does not guarantee the order of evaluation of expressions in the SELECT. So variables should not be assigned in one expression and then used in another -- they should be assigned in a single expression.
One way to handle this problem is by using session variables to track the changes of the values as ordered by your date column. In the query below, we keep track of the value, ordered by date, and assign a row number to each group of identical value. Then, only the first value in each group is retained. Note that this approach is robust to any number of duplicates. It is also robust with respect to there being gaps in your dates, so long as each record can be ordered by date.
SET #rn = 1;
SET #val = NULL;
SELECT t.val
FROM
(
SELECT
#rn:=CASE WHEN #val = val THEN #rn+1 ELSE 1 END rn,
#val:=val AS val,
dt
FROM yourTable
ORDER BY dt
) t
WHERE t.rn = 1
ORDER BY t.dt;
Output:
Demo here:
Rextester
You can make use of lag and lead functions.
select y from (select y , lag(y,1,0) over (order by x) as prev_y from t1) where y <> prev_y;
Is it possible to get specific row in query using like SUM?
Example:
id tickets
1 10 1-10 10=10
2 35 11-45 10+35=45
3 45 46-90 10+35+45=90
4 110 91-200 10+35+45+110=200
Total: 200 tickets(In SUM), I need to get row ID who have ticket with number like 23(Output would be ID: 2, because ID: 2 contains 11-45tickets in SUM)
You can do it by defining a local variable into your select query (in form clause), e.g.:
select id, #total := #total + tickets as seats
from test, (select #total := 0) t
Here is the SQL Fiddle.
You seem to want the row where "23" fits in. I think this does the trick:
select t.*
from (select t.*, (#total := #total + tickets) as running_total
from t cross join
(select #total := 0) params
order by id
) t
where 23 > running_total - tickets and 23 <= running_total;
SELECT
d.id
,d.tickets
,CONCAT(
TRIM(CAST(d.RunningTotal - d.tickets + 1 AS CHAR(10)))
,'-'
,TRIM(CAST(d.RunningTotal AS CHAR(10)))
) as TicketRange
,d.RunningTotal
FROM
(
SELECT
id
,tickets
,#total := #total + tickets as RunningTotal
FROM
test
CROSS JOIN (select #total := 0) var
ORDER BY
id
) d
This is similar to Darshan's answer but there are a few key differences:
You shouldn't use implicit join syntax, explicit join has more functionality in the long run and has been a standard for more than 20 years
ORDER BY will make a huge difference on your running total when calculated with a variable! if you change the order it will calculate differently so you need to consider how you want to do the running total, by date? by id? by??? and make sure you put it in the query.
finally I actually calculated the range as well.
And here is how you can do it without using variables:
SELECT
d.id
,d.tickets
,CONCAT(
TRIM(d.LowRange)
,'-'
,TRIM(
CAST(RunningTotal AS CHAR(10))
)
) as TicketRange
,d.RunningTotal
FROM
(
SELECT
t.id
,t.tickets
,CAST(COALESCE(SUM(t2.tickets),0) + 1 AS CHAR(10)) as LowRange
,t.tickets + COALESCE(SUM(t2.tickets),0) as RunningTotal
FROM
test t
LEFT JOIN test t2
ON t.id > t2. id
GROUP BY
t.id
,t.tickets
) d
Couldn't really explain my problem with words, but with an example I can show it clearly:
I have a table like this:
id num val
0 3 10
1 5 12
2 7 12
3 11 15
And I want to go through all the rows, and calculate the increase of the "num", and multiply that difference with the "val" value. And when I calculated all of these, I want to add these results together.
This is the mathematical equation, that I want to run on the table:
Result = (3-0)*10 + (5-3)*12 + (7-5)*12 + (11-7)*15
138 = Result
Thank you.
You can do with mysql variables, but you will still get one record for each entry.
select
#lastTotal := #lastTotal + ( (yt.num - #lastNum) * yt.val ) thisLineTotal,
#lastNum := yt.num as saveForNextRow,
yt.id
from
yourTable yt,
( select #lastTotal := 0,
#lastNum := 0 ) sqlvars
order by
id
This SHOULD give you what you want to confirm the calculations to each record basis.
Now, to get the one record and one column result, you can wrap it such as
select
pq.thisLineTotal
from
(above entire query ) as pq
order by
pq.id DESC
limit 1
Assuming the IDs are consecutive as your sample data suggests, just join the table to itself:
select sum((t1.num-ifnull(t2.num,0))*t1.val) YourValue
from YourTable t1
left join YourTable t2
on t2.id = t1.id - 1;
http://www.sqlfiddle.com/#!2/40b9f/12
This will give you the total. Make sure to order in the order you wish - I have ordered by id
SET #runtot:=0;
SET #prevval:=0;
select max(rt) as total FROM (
SELECT
q.val,
q.num,
(#runtot := #runtot + (q.num- #prevval) * q.val) AS rt,
(#prevval := q.num) AS pv
FROM thetable q
ORDER by ID) tot
If you want to see the details of the calculation, leave out the outer select as so:
SET #runtot:=0;
SET #prevval:=0;
SELECT
q.val,
q.num,
(#runtot := #runtot + (q.num- #prevval) * q.val) AS rt,
(#prevval := q.num) AS pv
FROM thetable q
ORDER by ID
If it is possible to have negative numbers for your column values, using max(rt) won't work for the total. You should then use:
SET #runtot:=0;
SET #prevval:=0;
select #runtot as total FROM (
SELECT
q.val,
q.num,
(#runtot := #runtot + (q.num- #prevval) * q.val) AS rt,
(#prevval := q.num) AS pv
FROM thetable q
ORDER by ID) tot LIMIT 1
I'm ordering a recordset like this:
SELECT * FROM leaderboards ORDER BY time ASC, percent DESC
Say I have the id of the record which relates to you, how can I find out what position it is in the recordset, as ordered above?
I understand if it was just ordered by say 'time' I could
SELECT count from table where time < your_id
But having 2 ORDER BYs has confused me.
You can use a variable to assign a counter:
SELECT *, #ctr := #ctr + 1 AS RowNumber
FROM leaderboards, (SELECT #ctr := 0) c
ORDER BY time ASC, percent DESC
Does this do what you want?
SELECT count(*)
FROM leaderboards lb cross join
(select * from leaderboards where id = MYID) theone
WHERE lb.time < theone.time or
(lb.time = theone.time and lb.percent >= theone.percent);
This assumes that there are no duplicates for time, percent.