MySQL的SUM超过CASE语句

Question

可能有人请帮助我获得A_VAL的总和在SQL

下面

SELECT 
    CASE 
    WHEN COUNT(t.A_INS_NAM) = 10 THEN 1 
    WHEN COUNT(t.A_INS_NAM) = 20 THEN 2 
    WHEN COUNT(t.A_INS_NAM) BETWEEN 30 AND 50 THEN 3 
    WHEN COUNT(t.A_INS_NAM) > 50 THEN 5 
    ELSE 'some value' 
    END AS A_VAL 
FROM 
    TABLE1 t 
    JOIN IWD t1 ON(t.A_INS_NAM = t1.A_INS_NAM) 
    JOIN TIM t2 ON(t1.IWD = t2.IM_ID) 
    JOIN TWS t3 ON(t2.IM_ID = t3.T_ID) 
WHERE t3.TN = 'abced' 
    AND t.A_DATE BETWEEN '2014-01-01' AND '2015-05-01' 
    AND t.A_INS_NAM NOT LIKE '%pk%' 

Answer 1

您可以使用select来计算总和一分，注意，您使用的是聚合函数没有GROUP BY它将导致为单排

SELECT SUM(A_VAL) 
FROM (
    SELECT 
     CASE 
     WHEN COUNT(t.A_INS_NAM) = 10 THEN 1 
     WHEN COUNT(t.A_INS_NAM) = 20 THEN 2 
     WHEN COUNT(t.A_INS_NAM) BETWEEN 30 AND 50 THEN 3 
     WHEN COUNT(t.A_INS_NAM) > 50 THEN 5 
     ELSE 'some value' 
     END AS A_VAL 
    FROM 
     TABLE1 t 
     JOIN IWD t1 ON(t.A_INS_NAM = t1.A_INS_NAM) 
     JOIN TIM t2 ON(t1.IWD = t2.IM_ID) 
     JOIN TWS t3 ON(t2.IM_ID = t3.T_ID) 
    WHERE t3.TN = 'abced' 
     AND t.A_DATE BETWEEN '2014-01-01' AND '2015-05-01' 
     AND t.A_INS_NAM NOT LIKE '%pk%' 
) a