在有条件的情况下计数

Question

尝试计算有多少患者有某种类型的诊断，这应该返回3，但它返回5，所以想知道是否有一种方法可以计算多个条件的一列？

SELECT COUNT(Diagnosis_1) AS '85th %'
FROM   PROBLEM
WHERE  ENCOUNTER_DATE BETWEEN '01/06/2016' AND '01/06/16'
       AND DIAGNOSIS_1 = '27800'
        OR DIAGNOSIS_1 = 'V8553' 

Answer 1

检查逻辑运算和数据格式的优先级（'01/06/2016' == '01/06/16'）：

SELECT COUNT(Diagnosis_1) AS [85th %]
FROM PROBLEM
WHERE ENCOUNTER_DATE = '20160601'
    AND DIAGNOSIS_1 IN ('27800', 'V8553')