I am using sum function inside case statement. I want to do selective summation of rows.
case when
type in ('A','B')
then nvl(SUM(Amount_1),Amount)
else Amount
Two columns are there Amount and Amount_1 and for the Amount_1 column, I want to remove few rows based on some condition C1. For e.g. If I have 10 rows that have type in A and based on condition C1 I am getting only 8 rows then I want to sum Amount_1 column on the basis of 8 rows only.
I think you have the basic logic understood correctly, but your syntax is a bit off. You should be using the CASE expression inside the SUM() function, not the other way around.
SELECT type,
SUM(CASE WHEN type IN ('A', 'B')
THEN COALESCE(Amount_1, Amount) ELSE Amount END) AS type_sum -- ELSE 0 ?
FROM yourTable
This will compute the sum of COALESCE(Amount_1, Amount) for those records where the type is either A or B, otherwise it will use Amount in the sum. If you intended to not count non-matching records at all, then modify my query by using ELSE 0 in the CASE expression.
Related
I have a scenario where I'm trying not to count a row where it has a zero, blank or NULL. But I'm not sure how to. I have used ISNULL to replace it with blank but the result shows zero. I don't want zero because it messes up my averages etc. The screen shot below should show 17 in the bottom as total but it's showing 18 because it's counting the null as row count. This null row has an N/A as a value in the data set but my count counts it as a row. I'm using count() because I have many other columns so I can not change the count(). Any ideas on how to show the total as 17 instead of 18?
Thank you
Some SQL implementations (I think this is also proper ANSI standard but don't know that for sure) exhibit a different behaviour for COUNT(*) VS COUNT(field).
The former will include NULLs, the latter will exclude them.
you can use SUM like this
SELECT SUM(CASE WHEN ISNULL(testeq4,'') <> '' THEN 1 ELSE 0 end)
FROM YourTable
Try this:
SELECT SUM(CASE WHEN ISNULL(TestQ4,0)=0 THEN 0 ELSE 1 END)
Given a table of random numbers as follows:
** Person table schema **
Name
Marks1
Marks2
I want to return a table with similar structure and headings, where if the sum of a column is odd, the column shows the maximum value for that column, and when the sum is even, it shows the minimum value by using a case statement.
** output table schema **
Marks1
Marks2
I've tried the following code.
select Marks1,Marks2 ,
(case
when mod(sum(Marks1),2)=0 then
min(Marks1)
else max(Marks1)
end) as Marks1 ,
(case
when mod(sum(Marks2),2)=0 then
min(Marks2)
else max(Marks2)
end) as Marks2
from numbers
group by Marks1;
Sample output -
TABLE
Ash 56 45
David 45 35
Output -
56 35
As 56+45 = 101 odd number so output 56(max number). Whereas in marks2 column, 45+35 =80, even number so output 35(min number).
Can anyone tell me what's wrong with it? Thanks in advance.
Use a CTE to get your min(), max(), and sum() values. Then use case to determine what values to display.
Since your problem statement and sample results do not match, I followed your sample results to return max() on an odd sum(). You can switch this by changing the two case statements from 1 to 0.
Working fiddle
with totals as (
select sum(marks1) as marks1sum,
min(marks1) as marks1min,
max(marks1) as marks1max,
sum(marks2) as marks2sum,
min(marks2) as marks2min,
max(marks2) as marks2max
from numbers
)
select case mod(marks1sum, 2)
when 1 then marks1max
else marks1min
end as marks1,
case mod(marks2sum, 2)
when 1 then marks2max
else marks2min
end as marks2
from totals;
You are reusing marks1 and marks2 when aliasing your third and fourth column which is colliding. Try using different name.
Using Microsoft SQL Server, if you use COUNT(column name) it returns the number of rows in that column which have a non-null value (i.e., it counts the rows, ignoring nulls).
Is there any way to do something similar, but allowing you to tell it which values to ignore? For example, if I wanted to count all the rows in a table which have a value which is NOT 1, I could do something like COUNTNOT(column name,1). That would count all the rows in the specified column which have a value NOT 1.
You may use conditional aggregation:
SELECT COUNT(CASE WHEN some_val <> 1 THEN 1 END) AS cnt
FROM yourTable;
The above logic is that COUNT will count one whenever some value is not equal to 1. Otherwise, it falls on the ELSE conditional, which if not present defaults to the value NULL. Since NULL is not counted, any value other than 1 would contribute zero to the count.
Why not put what you want to exclude in a WHERE clause?
SELECT COUNT(some_val) AS cnt
FROM yourTable
WHERE some_val <> 1
You need to be careful about NULL values. I would recommend:
select sum(case when column in (<values to ignore>) then 0 else 1 end)
This will count NULL values as not in the list (even if NULL is in the list). To ignore NULL values (as well), switch the logic to:
select sum(case when column not in (<values to ignore>) then 1 else 0 end)
and be sure NULL is not in the list.
i guess i just lack the keywords to search, but this is burning on my mind:
how can i add a condition to the sum-function in the select-statement like
select sum(a), sum(b where c=1) from db;?
this means, i want to see the sum of column a and the sum of column b, but only of the records in column b of which column c has the value 1.
the output of heidi just says "bad syntac near WHERE". may there be any other way?
thanks in advance and best regards from Berlin, joachim
The exact syntax may differ depending on the database engine, however it will be along the lines of
SELECT
sum(a),
sum(CASE WHEN c = 1 THEN b ELSE 0 END)
FROM
db
select sum(case when c=1 then b else 0 end)
This technique is useful when you need a lot of aggregates on the same set of data - you can query the entire table without applying a where filter, and have a bunch of these which give you aggregated data for a specific filter.
It's also useful when you need a lot of counts based on filters - you can do sums of 1 or 0:
select sum(case when {somecondition} then 1 else 0 end)
I have a table that has an integer column from which I am trying to get a few counts from. Basically I need four separate counts from the same column. The first value I need returned is the count of how many records have an integer value stored in this column between two values such as 213 and 9999, including the min and max values. The other three count values I need returned are just the count of records between different values of this column. I've tried doing queries like...
SELECT (SELECT Count(ID) FROM view1 WHERE ((MyIntColumn BETWEEN 213 AND 9999));)
AS Value1, (SELECT Count(ID) FROM FROM view1 WHERE ((MyIntColumn BETWEEN 500 AND 600));) AS Value2 FROM view1;
So there are for example, ten records with this column value between 213 and 9999. The result returned from this query gives me 10, but it gives me the same value of 10, 618 times which is the number of total records in the table. How would it be possible for me to only have it return one record of 10 instead?
Use the Iif() function instead of CASE WHEN
select Condition1: iif( ), condition2: iif( ), etc
P.S. : What I used to do when working with Access was have the iif() resolve to 1 or 0 and then do a SUM() to get the counts. Roundabout but it worked better with aggregation since it avoided nulls.
SELECT
COUNT(CASE
WHEN MyIntColumn >= 213 AND MyIntColumn <= 9999
THEN MyIntColumn
ELSE NULL
END) AS FirstValue
, ??? AS SecondValue
, ??? AS ThirdValue
, ??? AS FourthValue
FROM Table
This doesn't need nesting or CTE or anything. Just define via CASE your condition within COUNTs argument.
I dont really understand what You want in the second, third an fourth column. Sounds to me, its very similar to the first one.
Reformatted, your query looks like:
SELECT (
SELECT Count(ID)
FROM view1
WHERE MyIntColumn BETWEEN 213 AND 9999
) AS Value1
FROM view1;
So you are selecting a subquery expression that is not related to the outer query. For each row in view1, you calculate the number of rows in view1.
Instead, try to do the calculation once. You just have to remove your outer query:
SELECT Count(ID)
FROM view1
WHERE MyIntColumn BETWEEN 213 AND 9999;
OLEDB Connection in MS Access does not support key words CASE and WHEN .
You can only use iif() function to count two, three.. values in same columns
SELECT Attendance.StudentName, Count(IIf([Attendance]![Yes_No]='Yes',1,Null)) AS Yes, Count(IIf([Attendance]![Yes_No]='No',1,Null)) AS [No], Count(IIf([Attendance]![Yes_No]='Not',1,Null)) AS [Not], Count(IIf([Attendance]![Yes_No],1,Null)) AS Total
FROM Attendance
GROUP BY Attendance.StudentName;