在SQL中将一个查询的结果计算为另一个查询的百分比

Question

我正在尝试根据视力检查的人数来计算视力受损的人数。我已经成功地计算了视力受损的人的总数（TotalDiagnosed）和评估的总数（TotalEvaluated）：

! impala-shell -q 'SELECT COUNT(*) FROM (SELECT DISTINCT eyesight_evaluation.patient_id FROM eyesight_evaluation WHERE severity_of_sight_loss IN ("Slight","Mild","Moderate","Moderately Severe","Severe","Profound")) AS TotalDiagnosed;'

! impala-shell -q 'SELECT COUNT(DISTINCT eyesight_evaluation.patient_id) AS TotalEvaluated FROM eyesight_evaluation;'

我不确定如何确定百分比。我尝试过

! impala-shell -q 'SELECT COUNT(DISTINCT eyesight_evaluation.patient_id) AS TotalEvaluated FROM eyesight_evaluation;'

但它返回了

错误：AnalysisException：第1行中的语法错误：...已选择，TotalEvaluated ROUND（已诊断总数* 100.0 /总...^遇到：（预期值：CROSS，FROM，FULL，GROUP，HAVING，INNER，JOIN，LEFT，LIMIT，OFFSET，ON，ORDER，RIGHT，> STRAIGHT_JOIN，TABLESAMPLE，UNION，USING，WHERE，COMMA

原因：异常：语法错误

有人可以帮我确定百分比吗？我正在使用Impala和Jupyter笔记本。

Answer 1

SELECT (COUNT(DISTINCT CASE WHEN severity_of_sight_loss IN ('Slight', 'Mild', 'Moderate', 'Moderately Severe', 'Severe', 'Profound') THEN ee.patient_id END) * 1.0 /
        COUNT(DISTINCT eyesight_evaluation.patient_id)
       )
FROM eyesight_evaluation ee;