Selecting COUNT(*) with DISTINCT
Solution 1:
Count all the DISTINCT program names by program type and push number
SELECT COUNT(DISTINCT program_name) AS Count,
program_type AS [Type]
FROM cm_production
WHERE push_number=@push_number
GROUP BY program_type
DISTINCT COUNT(*)
will return a row for each unique count. What you want is COUNT(DISTINCT <expression>)
: evaluates expression for each row in a group and returns the number of unique, non-null values.
Solution 2:
I needed to get the number of occurrences of each distinct value. The column contained Region info. The simple SQL query I ended up with was:
SELECT Region, count(*)
FROM item
WHERE Region is not null
GROUP BY Region
Which would give me a list like, say:
Region, count
Denmark, 4
Sweden, 1
USA, 10
Solution 3:
You have to create a derived table for the distinct columns and then query the count from that table:
SELECT COUNT(*)
FROM (SELECT DISTINCT column1,column2
FROM tablename
WHERE condition ) as dt
Here dt
is a derived table.
Solution 4:
SELECT COUNT(DISTINCT program_name) AS Count, program_type AS [Type]
FROM cm_production
WHERE push_number=@push_number
GROUP BY program_type