This question already has answers here:
How to count number of occurrences for all different values in database column?
(2 answers)
Closed 3 years ago.
I have a table like the following:
ID X Y
5 2 0
5 1 1
5 3 3
4 -2 1
4 0 0
3 5 -3
I would like to count how the records for each ID
ID count
5 3
4 2
3 1
This is pretty much all
SELECT ID, COUNT(*) AS count FROM TABLE GROUP BY ID
Related
I have 3 tables namely Question, Feedback and FeedbackResult. I wish to generate a report where I need to find the rating average against each question.
Questions
---------
QuestionId Question
1 Question 1
2 Question 2
3 Question 3
4 Question 4
5 Question 5
Feedback
--------
FeedbackId Questions QuestionCount
2 1,2,3,4,5 5 -- Questions column has questionid from Question table
FeedbackResults
---------------
FeedbackResId FeedbackId Answers
1 2 4,3,5,2,3 -- these answers are ratings(1 to 5) against each question
2 2 4,2,3,4,5 -- which means 4 is the rating for QuestionId 1, 2 is for QuestionId 2 etc
3 2 5,3,4,3,2
4 2 4,1,1,1,2
I wish to get result as average rating against each question
Question Rating
Question 1 3.5
Question 2 4
Question 3 5
Question 4 2
Question 5 4.5
Edit
Should I redesign the database table as
FeedbackResults
---------------
FeedbackResId FeedbackId QuetionID Answers UserId
1 2 4 4 1
2 2 1 3 1
3 2 5 3 1
4 2 1 2 2
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I have a table of data and have some records.
I want to change every fifth row of data and update the column ParentId to be equal of first row Id of five row group - like this:
Id ParentId ....
-------------------------------
1 1
2 3
3 10
4 5
5 5
6 5
7 2
8 2
9 2
10 2
11 2
12 7
13 7
and result I need in SQL Server should be like this:
Id ParentId ....
-------------------------------
1 1
2 1
3 1
4 1
5 1
6 6
7 6
8 6
9 6
10 6
11 11
12 11
13 11
...
You can use this code if you want update your table:
Update YourTable set ParentId= (Ceiling(Id*1.0/5)-1)*5 + 1
and if you want just select rows use this :
select Id, (Ceiling(Id*1.0/5)-1)*5 + 1 as ParentId from yourtable
update myTable
set ParentId = 5 * (Id / 5) + 1
where Id % 5 != 0
update myTable
set ParentId = 5 * ((Id /5) - 1) + 1
where Id % 5 = 0
This question already has an answer here:
How to reset cumsum after change in sign of values?
(1 answer)
Closed 4 years ago.
I have a dataframe with 2 columns, the objective here is simple ; reset the df.cumsum() if a row column is set to False;
df
value condition
0 1 1
1 2 1
2 3 1
3 4 0
4 5 1
the wanted result is as follows :
df
value condition
0 1 1
1 3 1
2 6 1
3 4 0
4 9 1
If i loop over the dataframe as described in this post Python pandas cumsum() reset after hitting max
i can achieve the wanted results, but i was looking for a more vectorized way using pandas standard functions
How about:
df['cSum'] = df.groupby((df.condition == 0).cumsum()).value.cumsum()
Output:
value condition cSum
0 1 1 1
1 2 1 3
2 3 1 6
3 4 0 4
4 5 1 9
You'll group consecutive rows together until you encounter a 0 in the condition column, and then you apply the cumsum within each group separately.
I have this table:
id sort_ord
0 6
1 7
2 2
3 3
4 4
5 5
6 8
Why does this query:
UPDATE table
SET sort_ord=(
SELECT count(*)
FROM table AS pq
WHERE sort_ord<table.sort_ord
ORDER BY sort_ord
)
WHERE(sort_ord>=0)
Produce:
id sort_ord
0 4
1 5
2 0
3 1
4 2
5 4
6 6
I was expecting all sort_ord fields to subtract by 2.
Here is defined: https://www.sqlite.org/isolation.html
About this link i can interpret, you has several instances for one query (update table and select count table) and independent of each other.
When you are in update sort_data(5) id 5, you have new data for read on every "SET sot_ord" (understanding what say about isolation), and now the result is 4.
Every select is a new instance and a new data reading
id sort_ord
0 4
1 5
2 0
3 1
4 2
5 5**
6 8**
From a given table I want to be able to sum values having the same number (should be easy, right?)
Problem: A given value can be assigned from 2 to n consecutive numbers.
For some reasons this information is stored in a single row describing the value, the starting number and the ending number as below.
TABLE A
id | starting_number | ending_number | value
----+-----------------+---------------+-------
1 2 5 8
2 0 3 5
3 4 6 6
4 7 8 10
For instance the first row means:
value '8' is assigned to numbers: 2, 3 and 4 (5 is excluded)
So, I would like the following intermediairy result table
TABLE B
id | number | value
----+--------+-------
1 2 8
1 3 8
1 4 8
2 0 5
2 1 5
2 2 5
3 4 6
3 5 6
4 7 10
So I can sum 'value' for elements having identical 'number'
SELECT number, sum(value)
FROM B
GROUP BY number
TABLE C
number | sum(value)
--------+------------
2 13
3 8
4 14
0 5
1 5
5 6
7 10
I don't know how to do this and didn't find any answer on the web (maybe not looking with appropriate key words...)
Any idea?
You can do what you want with generate_series(). So, TableB is basically:
select id, generate_series(starting_number, ending_number - 1, 1) as n, value
from tableA;
Your aggregation is then:
select n, sum(value)
from (select id, generate_series(starting_number, ending_number - 1, 1) as n, value
from tableA
) a
group by n;