Is it possible to specify condition in Count()?
SqlSql ServerTsqlSql Problem Overview
Is it possible to specify a condition in Count()
? I would like to count only the rows that have, for example, "Manager" in the Position column.
I want to do it in the count statement, not using WHERE
; I'm asking about it because I need to count both Managers and Other in the same SELECT
(something like Count(Position = Manager), Count(Position = Other))
so WHERE
is no use for me in this example.
Sql Solutions
Solution 1 - Sql
If you can't just limit the query itself with a where
clause, you can use the fact that the count
aggregate only counts the non-null values:
select count(case Position when 'Manager' then 1 else null end)
from ...
You can also use the sum
aggregate in a similar way:
select sum(case Position when 'Manager' then 1 else 0 end)
from ...
Solution 2 - Sql
Assuming you do not want to restrict the rows that are returned because you are aggregating other values as well, you can do it like this:
select count(case when Position = 'Manager' then 1 else null end) as ManagerCount
from ...
Let's say within the same column you had values of Manager, Supervisor, and Team Lead, you could get the counts of each like this:
select count(case when Position = 'Manager' then 1 else null end) as ManagerCount,
count(case when Position = 'Supervisor' then 1 else null end) as SupervisorCount,
count(case when Position = 'Team Lead' then 1 else null end) as TeamLeadCount,
from ...
Solution 3 - Sql
@Guffa 's answer is excellent, just point out that maybe is cleaner with an IF statement
select count(IIF(Position = 'Manager', 1, NULL)) as ManagerCount
from ...
Solution 4 - Sql
Depends what you mean, but the other interpretation of the meaning is where you want to count rows with a certain value, but don't want to restrict the SELECT
to JUST those rows...
You'd do it using SUM()
with a clause in, like this instead of using COUNT()
:
e.g.
SELECT SUM(CASE WHEN Position = 'Manager' THEN 1 ELSE 0 END) AS ManagerCount,
SUM(CASE WHEN Position = 'CEO' THEN 1 ELSE 0 END) AS CEOCount
FROM SomeTable
Solution 5 - Sql
If using Postgres or SQLite, you can use the Filter clause to improve readability:
SELECT
COUNT(1) FILTER (WHERE POSITION = 'Manager') AS ManagerCount,
COUNT(1) FILTER (WHERE POSITION = 'Other') AS OtherCount
FROM ...
BigQuery also has Countif
- see the support across different SQL dialects for these features here:
https://modern-sql.com/feature/filter
Solution 6 - Sql
You can also use the Pivot Keyword if you are using SQL 2005 or above
SELECT *
FROM @Users
PIVOT (
COUNT(Position)
FOR Position
IN (Manager, CEO, Employee)
) as p
Test Data Set
DECLARE @Users TABLE (Position VARCHAR(10))
INSERT INTO @Users (Position) VALUES('Manager')
INSERT INTO @Users (Position) VALUES('Manager')
INSERT INTO @Users (Position) VALUES('Manager')
INSERT INTO @Users (Position) VALUES('CEO')
INSERT INTO @Users (Position) VALUES('Employee')
INSERT INTO @Users (Position) VALUES('Employee')
INSERT INTO @Users (Position) VALUES('Employee')
INSERT INTO @Users (Position) VALUES('Employee')
INSERT INTO @Users (Position) VALUES('Employee')
INSERT INTO @Users (Position) VALUES('Employee')
Solution 7 - Sql
Do you mean just this:
SELECT Count(*) FROM YourTable WHERE Position = 'Manager'
If so, then yup that works!
Solution 8 - Sql
I know this is really old, but I like the NULLIF
trick for such scenarios, and I found no downsides so far. Just see my copy&pasteable example, which is not very practical though, but demonstrates how to use it.
NULLIF
might give you a small negative impact on performance, but I guess it should still be faster than subqueries.
DECLARE @tbl TABLE ( id [int] NOT NULL, field [varchar](50) NOT NULL)
INSERT INTO @tbl (id, field)
SELECT 1, 'Manager'
UNION SELECT 2, 'Manager'
UNION SELECT 3, 'Customer'
UNION SELECT 4, 'Boss'
UNION SELECT 5, 'Intern'
UNION SELECT 6, 'Customer'
UNION SELECT 7, 'Customer'
UNION SELECT 8, 'Wife'
UNION SELECT 9, 'Son'
SELECT * FROM @tbl
SELECT
COUNT(1) AS [total]
,COUNT(1) - COUNT(NULLIF([field], 'Manager')) AS [Managers]
,COUNT(NULLIF([field], 'Manager')) AS [NotManagers]
,(COUNT(1) - COUNT(NULLIF([field], 'Wife'))) + (COUNT(1) - COUNT(NULLIF([field], 'Son'))) AS [Family]
FROM @tbl
Comments appreciated :-)
Solution 9 - Sql
Note with PrestoDB SQL (from Facebook), there is a shortcut:
https://prestodb.io/docs/current/functions/aggregate.html
> count_if(x) → bigint > > Returns the number of TRUE input values. This > function is equivalent to count(CASE WHEN x THEN 1 END)
Solution 10 - Sql
Here is what I did to get a data set that included both the total and the number that met the criteria, within each shipping container. That let me answer the question "How many shipping containers have more than X% items over size 51"
select
Schedule,
PackageNum,
COUNT (UniqueID) as Total,
SUM (
case
when
Size > 51
then
1
else
0
end
) as NumOverSize
from
Inventory
where
customer like '%PEPSI%'
group by
Schedule, PackageNum
Solution 11 - Sql
SELECT COUNT(*) FROM bla WHERE Position = 'Manager'
Solution 12 - Sql
I think you can use a simple WHERE clause to select only the count some record.