Предполагается, что имя пользователя также существует в таблице SALES
SELECT Username,SUM(Yes) As Yes, SUM(`Not`) As `Not`
, SUM(Other) As Other, SUM(sales) Sales, SUM(total)
FROM (
-- get diary data
SELECT username,mobileNo As mobile,
CASE WHEN D.type = 'Yes' THEN 1 ELSE 0 END as Yes,
CASE WHEN D.type = 'Not' THEN 1 ELSE 0 END as `Not`,
CASE WHEN D.type = '' THEN 1 ELSE 0 END as Other,
0 As sales, 1 as total
FROM dairy as D
WHERE source = 'Network'
AND UNIX_TIMESTAMP(CheckDate) >= 1309474800
AND UNIX_TIMESTAMP(CheckDate) <= 1311894000
UNION ALL
-- get all sales
SELECT DISTINCT username,mobile, 0 as Yes, 0 as `Not`, 0 As Other, 1 As sales, 0 As total
FROM sales
WHERE UNIX_TIMESTAMP(CheckDate) >= 1309474800
AND UNIX_TIMESTAMP(CheckDate) <= 1311894000
) AS a
GROUP BY Username
Также попробуйте исходный запрос с добавлением даты
SELECT D.Username,
SUM(CASE WHEN D.type = 'Yes' THEN 1 ELSE 0 END) as Yes,
SUM(CASE WHEN D.type = 'Not' THEN 1 ELSE 0 END) as Not,
SUM(CASE WHEN D.type = '' THEN 1 ELSE 0 END) as Other,
SUM(CASE WHEN S.mobile IS NULL THEN 0 ELSE 1 END) as Sales,
COUNT(*) as TOTAL
FROM dairy as D
LEFT JOIN (SELECT DISTINCT mobile FROM sales WHERE UNIX_TIMESTAMP(CheckDate) >= 1309474800 AND UNIX_TIMESTAMP(CheckDate) <= 1311894000 ) as S on D.MobileNo = S.mobile
WHERE source = 'Network'
AND UNIX_TIMESTAMP(CheckDate) >= 1309474800
AND UNIX_TIMESTAMP(CheckDate) <= 1311894000
GROUP BY D.Username
ORDER BY TOTAL DESC