I have two tables in my MySQL database: allele
and locus
. I want to know for a given locus how many alleles there are and of those how many have the status Tentative
. I currently have the following query with subquery:
SELECT COUNT(*) as alleleCount,
(SELECT COUNT(*)
FROM allele
INNER JOIN locus ON allele.LocusID = locus.PrimKey
WHERE Status = 'Tentative'
AND locus.ID = 762
) as newAlleleCount
FROM allele
INNER JOIN locus ON allele.LocusID = locus.PrimKey
WHERE locus.ID = 762
but I feel there must be a better way to write this query.
You can use SUM()
using sum with condition will result in a boolean 1 or 0 so it will give you the count for your conditions
SELECT locus.ID,COUNT(*) `all_alleles_per_locus`,
SUM(Status = 'Tentative') `tentative_alleles_762`
FROM allele
INNER JOIN locus ON allele.LocusID = locus.PrimKey
GROUP BY locus.ID
One way would be to group the locus by its statuses and fetch each status's respective count; using the WITH ROLLUP
modifier will add a NULL
status at the end representing the total:
SELECT status, COUNT(*)
FROM allele JOIN locus ON locus.PrimKey = allele.LocusID
WHERE locus.ID = 762
GROUP BY status WITH ROLLUP
If you absolutely do not want a list of all statuses, you can instead GROUP BY status = 'Tentative'
(optionally WITH ROLLUP
if desired)—but it will not be sargable.
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