Try using a left outer join & COUNT(DISTINCT ...)
SELECT COUNT(DISTINCT l.identifier) AS regCount
FROM list AS l LEFT OUTER JOIN person AS p ON l.identifier = p.list_identifier
WHERE l.Name LIKE '%a%'
문제
I'm using for count:
SELECT l.identifier AS id, l.name AS listName, COUNT(p.list_identifier)
AS regCount FROM list AS l LEFT JOIN person AS p ON l.identifier = p.list_identifier
WHERE p.list_identifier IS NULL GROUP BY l.name;
Help me, please.
해결책
Try using a left outer join & COUNT(DISTINCT ...)
SELECT COUNT(DISTINCT l.identifier) AS regCount
FROM list AS l LEFT OUTER JOIN person AS p ON l.identifier = p.list_identifier
WHERE l.Name LIKE '%a%'