记录一个表，COUNT多列的写法

笔记

DHS_CARDIOVASCULAR_SCREENING  为病人数据表，需要查出糖尿病、高血压、脑卒中家族史的病人各有多少个。

SELECT
COUNT(D.ID) AS TOTAL,
COUNT(CASE
WHEN D.DIABETES = '1' THEN
'DIABETES'
END) DIABETES_COUNT, -- 糖尿病

COUNT(CASE
WHEN D.HYPERTENSION = '1' THEN
'HYPERTENSION'
END) HYPERTENSIONCOUNT, -- 高血压病

COUNT(CASE
WHEN D.STROKE_FAMILY_HIS = '1' THEN
'STROKE_FAMILY_HIS'
END) STROKE_FAMILY_HISCOUNT -- 脑卒中家族史

FROM DHS_CARDIOVASCULAR_SCREENING D