SELECT CASE WHEN AGE <= 10 THEN '1' WHEN AGE > 10 AND AGE <= 20 THEN '2' WHEN AGE > 20 AND AGE <= 30 THEN '3' WHEN AGE > 30 AND AGE <= 40 THEN '4' WHEN AGE > 40 AND AGE <= 50 THEN '5' WHEN AGE > 50 AND AGE <= 60 THEN '6' WHEN AGE > 60 AND AGE <= 70 THEN '7' WHEN AGE > 70 AND AGE <= 80 THEN '8' WHEN AGE > 80 AND AGE <= 90 THEN '9' WHEN AGE > 90 AND AGE <= 100 THEN 'a' WHEN AGE > 100 THEN 'b' END allshuju ,COUNT(*) renshu,OUT_MAIN_DIAG_RST leibie FROM WORK_BASY_DATA where 1=1 and OUT_DT >= '2012-10-1' and OUT_DT <= '2012-10-31' GROUP BY allshuju,OUT_MAIN_DIAG_RST having OUT_MAIN_DIAG_RST!='' AND allshuju!=''

sqlserver 中也有 case when 一样的

一样

mysql和sql server差别不大

SQL Server也支持CASE WHEN，但你的写法在SQL Server会有问题，你的语句中allshuju不是实际的字段，而是一个别名，不能再GROUP BY中直接用
要不你把GROUP BY和HAVING后的allshuju换成上面的CASE WHEN完整判断，要不就在嵌套一层

 SELECT t.allshuju,t.OUT_MAIN_DIAG_RST ,COUNT(*) renshu FROM (
    SELECT 
    CASE 
    WHEN AGE <= 10 THEN '1' 
    WHEN AGE > 10 AND AGE <= 20 THEN '2' 
    WHEN AGE > 20 AND AGE <= 30 THEN '3' 
    WHEN AGE > 30 AND AGE <= 40 THEN '4' 
    WHEN AGE > 40 AND AGE <= 50 THEN '5' 
    WHEN AGE > 50 AND AGE <= 60 THEN '6' 
    WHEN AGE > 60 AND AGE <= 70 THEN '7' 
    WHEN AGE > 70 AND AGE <= 80 THEN '8' 
    WHEN AGE > 80 AND AGE <= 90 THEN '9' 
    WHEN AGE > 90 AND AGE <= 100 THEN 'a' 
    WHEN AGE > 100 THEN 'b' END allshuju 
    ,OUT_MAIN_DIAG_RST leibie 
    FROM WORK_BASY_DATA 
    where 1=1 and OUT_DT >= '2012-10-1' and OUT_DT <= '2012-10-31' 
) t 
GROUP BY t.allshuju,t.OUT_MAIN_DIAG_RST 
having t.OUT_MAIN_DIAG_RST!='' AND t.allshuju!=''