Можете да го направите, като използвате корелирани подзаявки като това:
SELECT
Company,
Date,
(SELECT COUNT(*) FROM MyTable AS T1
WHERE T1.Flag='Y' AND T1.Company=T2.Company AND T1.Date=T2.Date) AS Count_Y,
(SELECT COUNT(*) FROM MyTable AS T1
WHERE T1.Flag='N' AND T1.Company=T2.Company AND T1.Date=T2.Date) AS Count_N
FROM MyTable AS T2
GROUP BY Company, Date
Можете също да го направите по-сбито, но може би с (вероятно) малко по-малко четливост, като използвате SUM
трик:
SELECT
Company,
Date,
SUM(CASE WHEN Flag='Y' THEN 1 ELSE 0 END) AS Count_Y,
SUM(CASE WHEN Flag='N' THEN 1 ELSE 0 END) AS Count_N,
FROM MyTable
GROUP BY Company, Date
В Oracle/PLSQL, DECODE
може да се използва за заместване на CASE
за още по-сбито:
SELECT
Company,
Date,
SUM(DECODE(Flag,'Y',1,0)) AS Count_Y,
SUM(DECODE(Flag,'N',1,0)) AS Count_N,
FROM MyTable
GROUP BY Company, Date