How to count the rows which contains non zero values in sql - sql

SELECT round(COUNT(dmd_1wk),2) AS NBR_ITEMS_1WK
FROM table;
Field dmd_1wk has so many zeros in it. How do I Count the non zero values?

It sounds like you just need to add a WHERE clause:
SELECT
round(COUNT(dmd_1wk),2) AS NBR_ITEMS_1WK
FROM table
WHERE dmd_1wk <> 0;
If you want the count of both non-zero and zero values, then you can use something like:
SELECT
round(COUNT(case when dmd_1wk <> 0 then dmd_1wk end),2) AS NBR_ITEMS_1WK_NonZero,
round(COUNT(case when dmd_1wk = 0 then dmd_1wk end),2) AS NBR_ITEMS_1WK_Zero
FROM table;

Method 1: Case Statement. This may be useful if you need to continue to process all rows (which a where clause would prevent).
SELECT count(case when dmd_1wk = 0 then 0 else 1 end) as NonZeroCount FROM MyTable
Method 2: Where Clause.
SELECT
count(1) as NonZeroCount
FROM
MyTable
WHERE
dmd_1wk <> 0

I'd like to offer another solution using NULLIF since COUNT won't count NULL values:
SELECT round(COUNT(NULLIF(dmd_1wk,0)),2) AS NBR_ITEMS_1WK
FROM table;
And here is the Fiddle.
Good luck.

Methinks bluefeets answer is probably what you are really looking for, as it sounds like you just want to count non-zeros; but this will get you a count of zero and non-zero items if that's not the case:
SELECT
ROUND(SUM(CASE NVL(dmd_1wk, 0) = 0 THEN 1 ELSE 0 END), 2) AS "Zeros",
ROUND(SUM(CASE NVL(dmd_1wk, 0) != 0 THEN 1 ELSE 0 END), 2) AS "NonZeros"
FROM table
Although there is no point in rounding a whole number, I've included your original ROUNDs as I'm guessing you're using it for formatting, but you might want to use:
TO_CHAR(SUM(...), '999.00')
as that's the intended function for formatting numbers.

You can filter them.
SELECT round(COUNT(dmd_1wk),2) AS NBR_ITEMS_1WK
FROM table
WHERE dmd_1wk <> 0;

Related

Is there a way to contruct this kind of result using group by in sql?

I have a table which consists of data where in I'm having trouble counting the corresponding rows.
Here is the sample table:
I am expecting an output like this:
You can do conditional aggregation:
select
sum(case when result = 'X' then 1 else 0 end) count_x,
sum(case when result is null then 1 else 0 end) count_blank
from mytable
I assume that by blank you mean null. If not, then you can change the condition in the second sum() from result is null to result = ''.
If you are running MySQL, this can be shortened a little:
select
sum(result = 'X') count_x,
sum(result is null) count_blank
from mytable

Why does this not return 0

I have a query like:
select nvl(nvl(sum(a.quantity),0)-nvl(cc.quantityCor,0),0)
from RCV_TRANSACTIONS a
LEFT JOIN (select c.shipment_line_id,c.oe_order_line_id,nvl(sum(c.quantity),0) quantityCor
from RCV_TRANSACTIONS c
where c.TRANSACTION_TYPE='CORRECT'
group by c.shipment_line_id,c.oe_order_line_id) cc on (a.shipment_line_id=cc.shipment_line_id and a.shipment_line_id=7085740)
where a.transaction_type='DELIVER'
and a.shipment_line_id=7085740
group by nvl(cc.quantityCor,0);
The query runs OK, but returns no value. I want it to return 0 if there is no quantity found. Where have I gone wrong?
An aggregation query with a GROUP BY returns no rows if all rows are filtered out.
An aggregation query with no GROUP BY always returns one row, even if all rows are filtered out.
So, just remove the GROUP BY. And change the SELECT to:
select coalesce(sum(a.quantity), 0) - coalesce(max(cc.quantityCor), 0)
I may be wrong, but it seems you merely want to subtract CORRECT quantity from DELIVER quantity for shipment 7085740. You don't need a complicated query for that. Especially your GROUP BY clauses make no sense if that is what you are after.
One way to write this query would be:
select
sum(case when transaction_type = 'DELIVER' then quantity else 0 end) -
sum(case when transaction_type = 'CORRECT' then quantity else 0 end) as diff
from rcv_transactions
where shipment_line_id = 7085740;
I had a query like this and was trying to return 'X' when the item is not valid.
SELECT case when segment1 is not null then segment1 else 'X' end
--INTO v_orgValidItem
FROM mtl_system_items_b
WHERE segment1='1676001000'--'Jul-00'--l_item
and organization_id=168;
..but it was returning NULL.
Changed to use aggregation with no group by and now it returns 'X' when the item is not valid.
SELECT case when max(segment1) is not null then max(segment1) else 'X' end valid
--INTO v_orgValidItem
FROM mtl_system_items_b
WHERE segment1='1676001000'--'Jul-00'--l_item
and organization_id=168;--l_ship_to_organization_id_pb;
Here is another example, proving the order of operations really matters.
When there is no match for this quote number, this query returns NULL:
SELECT MAX(NVL(QUOTE_VENDOR_QUOTE_NUMBER,0))
FROM PO_HEADERS_ALL
WHERE QUOTE_VENDOR_QUOTE_NUMBER='foo.bar';
..reversing the order of MAX and NVL makes all the difference. This query returns the NULL value condition:
SELECT NVL(MAX(QUOTE_VENDOR_QUOTE_NUMBER),0)
FROM PO_HEADERS_ALL
WHERE QUOTE_VENDOR_QUOTE_NUMBER='foo.bar';

Single use of COUNT in CASE WHEN

I have a column MessageId and have to take the count of distinct MessageId and if the result is 1, then have to display count as 0 else the count value itself. If the data set is more, using distinct twice is going to be a bit more time consuming.
...
CASE
WHEN count(DISTINCT MessageId) = 1
THEN 0
ELSE count(DISTINCT MessageId)
END as Count
...
Is there anyway to use COUNT(DISTINCT) only once using a single query itself? And also don't want to use multiple queries like assigning it to a variable and then using it.
Here is one method:
COALESCE(NULLIF(COUNT(DISTINCT MessageId), 1), 0)
it seems you need below
case when sum( case when MessageId= 1 then 1 else 0 end) =1
then 0 else
count(DISTINCT MessageId) end as cnt

SQL 2 counts with different filter

I have a table and I need calculate two aggregate functions with different conditions in one statement. How can I do this?
Pseudocode below:
SELECT count(CoumntA) *< 0*, count(CoumntA) * > 0*
FROM dbo.TableA
This is the same idea as tombom's answer, but with SQL Server syntax:
SELECT
SUM(CASE WHEN CoumntA < 0 THEN 1 ELSE 0 END) AS LessThanZero,
SUM(CASE WHEN CoumntA > 0 THEN 1 ELSE 0 END) AS GreaterThanZero
FROM TableA
As #tombom demonstrated, this can be done as a single query. But it doesn't mean that it should be.
SELECT
SUM(CASE WHEN CoumntA < 0 THEN 1 ELSE 0 END) AS less_than_zero,
SUM(CASE WHEN CoumntA > 0 THEN 1 ELSE 0 END) AS greater_than_zero
FROM
TableA
The time when this is not so good is...
- There is an index on CoumntA
- Most values (50% or more feels about right) are exactly zero
In that case, two queries will be faster. This is because each query can use the index to quickly home in on the section to be counted. In the end only counting the relevant records.
The example I gave, however, scans the whole table every time. Only once, but always the whole table. This is worth it when you're counting most of the records. In your case it looks liek you're counting most or all of them, and so this is probably a good way of doing it.
It is possible to do this in one select statement.
The way I've done it before is like this:
SELECT SUM(CASE WHEN ColumnA < 0 THEN 1 END) AS LessThanZero,
SUM(CASE WHEN ColumnA > 0 THEN 1 END) AS GreaterThanZero
FROM dbo.TableA
This is the correct MS SQL syntax and I believe this is a very efficient way of doing it.
Don't forget you are not covering the case when ColumnA = 0!
select '< 0' as filter, COUNT(0) as cnt from TableA where [condition 1]
union
select '> 0' as filter, COUNT(0) as cnt from TableA where [condition 2]
Be sure that condition 1 and condition 2 create a partition on the original set of records, otherwise same records could be counted in both groups.
For SQL Server, one way would be;
SELECT COUNT(CASE WHEN CoumntA<0 THEN 1 ELSE NULL END),
COUNT(CASE WHEN CoumntA>0 THEN 1 ELSE NULL END)
FROM dbo.TableA
Demo here.
SELECT
SUM(IF(CoumntA < 0, 1, 0)) AS lowerThanZero,
SUM(IF(CoumntA > 0, 1, 0)) AS greaterThanZero
FROM
TableA
Is it clear what's happening? Ask, if you have any more questions.
A shorter form would be
SELECT
SUM(CoumntA < 0) AS lowerThanZero,
SUM(CoumntA > 0) AS greaterThanZero
FROM
TableA
This is possible, since in MySQL a true condition is equal 1, a false condition is equal 0
EDIT: okay, okay, sorry, don't know why I thought it's about MySQL here.
See the other answers about correct syntax.

SQL Query - Return Text based on numeric value

I am trying to work out a query where the query will perform a count (total) on a specific column. If the count is greater than 0, I want to display YES and display NO if the returned count is zero.
So, if I a query as this:
SELECT COUNT(ProblemID)
FROM dbo.ProblemInfo
WHERE (ProblemID IN (100,101,309,305,205,600,500)) AND (DEPID = '10866')
that will actually be a subquery, how do I get the subquery to display "YES" when the returned count is greater than 0 and NO if the count is 0?
I appreciate any insight and help.
select isnull(
SELECT MAX('YES')
FROM dbo.ProblemInfo
WHERE ProblemID IN (100,101,309,305,205,600,500)
AND DEPID = '10866'),
'NO')
This is a trick to return either YES if there's at least one matching row, or null if not.
The wrapping isnull call then turns a null into a NO
Here's an alternate way of querying that.
IF EXISTS(
SELECT *
FROM dbo.ProblemInfo
WHERE (ProblemID IN (100,101,309,305,205,600,500))
AND (DEPID = '10866')
)
BEGIN
SELECT 'Yes'
END
ELSE
BEGIN
SELECT 'No'
END
What I like about this method is that, for enormous data-sets, it should be noticeably faster.
try
SELECT CASE
WHEN (SELECT COUNT(ProblemID) FROM dbo.ProblemInfo WHERE (ProblemID IN (100,101,309,305,205,600,500)) AND (DEPID = '10866')) > 0
THEN 'YES'
ELSE 'NO' END
FROM YourTable
you can use case when.
SELECT
case
when COUNT(ProblemID) = 0 then 'NO'
else 'YES'
end
FROM dbo.ProblemInfo WHERE (ProblemID IN (100,101,309,305,205,600,500)) AND (DEPID = '10866')