I have a table,
Name Seconds Status_measure
a 0 10
a 10 13
a 20 -1
a 30 15
a 40 20
a 50 12
a 60 -1
Here I want for a particular name a new column which is calculated by, "The number of times the value goes >-1 only after once the -1 is met" . So in this particular data I want a new column for the name "a" which has the value=3 , because once the -1 is reached in Status_measure, we have 3 values (15 and 20 and 12)>-1
Required data frame:
Id Name Seconds Status_measure Value
1 a 0 10 3
2 a 10 13 3
3 a 20 -1 3
4 a 30 15 3
5 a 40 20 3
6 a 50 12 3
7 a 60 -1 3
I tried doing
count(status_measure>-1) over (partition by name order by seconds)
But this is not giving any desired result
You can do it in 2 steps, group data, count entries of the grp = 1.
select *, sum(Status_measure > -1 and grp = 1) over(partition by name) n
from (
select *
, row_number() over(partition by name order by Seconds) - sum(Status_measure > -1 ) over(partition by name order by Seconds) grp
from tbl
) t
An option is using a variable update, which:
starts from 0
increases its value when reaches a -1
decreases its value when reaches a second -1
Once you have this column, you can run a sum over your values.
SET #change = 0;
SELECT *, SUM(CASE WHEN Status_measure = -1
THEN IF(#change=0, #change := #change + 1, #change := #change - 1)
ELSE #change END) OVER() -1 AS Value_
FROM tab
Check the demo here.
Limitations: this solution assumes you have only one range of interesting values between -1s.
Note: there's a -1 decrement from your sum because the first update of the variable will leave 1 in the same row of -1, which you don't want. For better understanding, comment out the application of SUM() OVER and see intermediate output.
More of a clarification to your question first. I want to expand your original data to include another row for the sake of 2 vs 3 entries. Also, is there some auto-increment ID in your data that the sequential consideration is applicable such as
Id Name Seconds Status_measure Value
1 a 0 10 3
2 a 10 13 3
3 a 20 -1 3
4 a 30 15 3
5 a 40 20 3
6 a 50 12 3
7 a 60 -1 3
If sequential, and you have IDs 1 & 2 above the -1 at ID #3. This would indicate two entries. But then for IDs 4-6 above -1 have a count of three entries before ID #7.
So, what "VALUE" do you want to have in your result. The max count of 3 for all rows, or would it be a value of 2 for ID#s 1, 2 and 3? And value of 3 for Ids 4-7? Or, do you want ALL entries to recognize the greatest count before -1 measure to show 3 for all entries.
Please EDIT your question, you can copy/paste this in your original question if need be and provide additional clarification as requested (auto-increment as well as that is an impact of final output / determining break).
Related
I have a MySQL table which has some records as follows:
unix_timestamp value
1001 2
1003 3
1012 1
1025 5
1040 0
1101 3
1105 4
1130 0
...
I want to compute the average for every 10 epochs to see the following results:
unix_timestamp_range avg_value
1001-1010 2.5
1011-1020 1
1021-1030 5
1031-1040 0
1041-1050 -1
1051-1060 -1
1061-1070 -1
1071-1080 -1
1081-1090 -1
1091-1100 -1
1101-1110 3.5
1111-1120 -1
1121-1130 0
...
I saw some similar answers like enter link description here and enter link description here and enter link description here but these answers are not a solution for my specific question. How can I get the above results?
The easiest way to do this is to use a calendar table. Consider this approach:
SELECT
CONCAT(CAST(cal.ts AS CHAR(50)), '-', CAST(cal.ts + 9 AS CHAR(50))) AS unix_timestamp_range,
CASE WHEN COUNT(t.value) > 0 THEN AVG(t.value) ELSE -1 END AS avg_value
FROM
(
SELECT 1001 AS ts UNION ALL
SELECT 1011 UNION ALL
SELECT 1021 UNION ALL
...
) cal
LEFT JOIN yourTable t
ON t.unix_timestamp BETWEEN cal.ts AND cal.ts + 9
GROUP BY
cal.ts
ORDER BY
cal.ts;
In practice, if you have the need to do this sort of query often, instead of the inline subquery labelled as cal above, you might want to have a full dedicated table representing all timestamp ranges.
using this command i can get TOP four values but some of the values are duplicate . so then wanted to swap based on serial number of table . using this bellow command to get the top four values now i want to swap any logic.
INPUT
SN Set name columname
1 100 Randy 25
2 100 many 22
3 100 sanny 22
4 100 nanny 35
Output
SN Set name columname
2 100 many 22
3 100 sanny 22
1 100 Randy 25
4 100 nanny 35
select top 4 * from filename where Set=100 order by columname DESC
Sort it based on column name then swap it based on serial number.
Wrap your query returning the wanted 4 rows up in a derived table, then do the opposite ORDER BY to get the wanted order:
select *
from
(
select top 4 * from filename where Set=100 order by columname DESC
) dt
order by columname ASC
In mysql, I need a query that returns the quantity of repeated values in the field "Info" of my table "Log".
Table Log:
ID_Log User Info
1 1 3
2 1 3
3 1 3
4 1 5
5 1 6
6 1 6
7 1 7
8 1 8
9 1 8
The query should return "4" (Info 3 appears three times, Info 6 appears two times, Info 8 appears two times).
Any suggestions?
You can get the number of values that have already appeared by using a simple subtraction. Subtract the number of distinct values from the total number of rows:
select count(*) - count(distinct info)
from log;
The difference is the number that "repeat".
This should work. Group the values of info together and only keep the results where the number of occurrences minus 1 is greater than 0. Then sum the numbers of occurrences.
select sum(repeats)
from (SELECT Info, count(*) - 1 AS repeats
FROM Log
GROUP BY Info
HAVING repeats > 0)
I want to select some rows with a specific filter, but don't limit if I don't get, at least, 40 rows.
It's a pseudo-example:
SELECT * FROM `table`
WHERE
SUM(1) < 40 OR
`age` > 18
It's similar to LIMIT, but LIMIT will consider the WHERE filter ever. I want to ignore the filter if I don't have at least 40 rows (but accept the firsts rows).
How I do that?
Edit: a lot of people had doubts what I really wanted.
This is an example:
ID AGE
1 10
2 20
3 30
4 10
5 20
6 30
7 10
I want to get the first 2 rows EVER. And only after at least two rows, get new rows that match the given conditions (WHERE).
For example: I want the first 2 rows more rows whose age is 30. The result would be equivalent to:
ID AGE
1 10 <first>
2 20 <second>
3 30 <conditional>
6 30 <conditional>
You can use an increasing variable #rownum to simulate the same functionality. However, this is much less efficient than limit because the server brings the filtered-out rows into memory and continuously performs the #rownum:=#rownum+1 calculation.
SELECT #rownum:=#rownum+1, t.*
FROM `table` t, (SELECT #rownum:=0) r
WHERE
#rownum <= 40 OR
`age` > 18
I have the table below
relID value charge
1 2 5
1 8 2
2 1 10
2 4 6
2 9 2
For the above table i need for a given value ex 10 to find what to charge for each relID
In the above for value<10 i need to get charge=5 for relID=1 and charge=2 for relID=2
I am trying to use 1 sql command to get it and i am kind of lost
Can anyony help
Thanks
Your question isn't very clear but I think this will work for you
SELECT t.relID,
(
SELECT charge
FROM table
WHERE relID = t.relID
AND value < 10
ORDER BY value
LIMIT 1
) AS charge
FROM table AS t
Let me rephrase.
Here is the table
relID value charge
1 2 5
1 8 2
2 1 10
2 4 6
2 9 2
Explain the table :
Lets say that the value and charge are money.
If the user has value 2 then i must charge with 5 using relID 1
If the user has value 8 then i must charge with 2 using relID 1
same for the relID 2
So when a user come with a value 10 i must find what to charge.So for the given value 10 i must find in the table all records with value<10.
In the example the values for value <10 are
For relID=1 are (2,8)
For relID=2 are (1,4,9)
Now for each relID i need to get the max value.
For relID=1 max value is 8 so charge is 2
For relID=2 max value is 9 so charge is 2
I plain english there are value rate
0-2 charge 5
2-8 charge 2
and ...
i hope to be clear now
select *
from Table t
where value =
(select max(value)
from Table
where value <= 10
and relId = t.relId)