Question

我有这个问题：

SELECT 
    CASE 
        WHEN COUNT(DISTINCT Q.FIELD_1) > 1 AND MAX(Q.FIELD_1) <> 'N/A' THEN 'VALUE_010' ELSE 'VALUE_011' END AS FIELD_1,
    CASE
        WHEN COUNT(DISTINCT Q.FIELD_2) = 10 AND MAX(Q.FIELD_2) <> 'N/A' THEN 'VALUE_020' 
        WHEN COUNT(DISTINCT Q.FIELD_2) = 100 AND MAX(Q.FIELD_2) <> 'N/A' THEN 'VALUE_021'   
        ELSE 'VALUE_022' END AS FIELD_2
FROM (
    SELECT 
        A.FIELD_1,
        B.FIELD_2
    FROM TABLE_A a
    JOIN TABLE_B b
        ON a.FIELD_X = b.FIELD_Y
    GROUP BY
        A.FIELD_1,
        B.FIELD_2
) Q

我想要的是在select的CASE / WHEN条件中使用COUNT或MAX等聚合函数。实际上我得到错误：“＆gt;附近的语法不正确”。是否有可能或我应该尝试不同的方法？

Answer 1

我认为这是因为您的代码中的FIELD_2之后有一个逗号

ELSE 'VALUE_022' END AS FIELD_2,

Answer 2

在您的查询中，style

中有一个逗号逗号

否则尝试

ELSE 'VALUE_022' END AS FIELD_2,

Answer 3

试试这个

SELECT 
    CASE WHEN COUNT(DISTINCT a.FIELD_1) > 1 THEN 'VALUE_010' ELSE 'VALUE_011' END AS FIELD_1
    ,CASE
        WHEN COUNT(DISTINCT b.FIELD_2) = 10 THEN 'VALUE_020' 
        WHEN COUNT(DISTINCT b.FIELD_2) = 100 THEN 'VALUE_021'   
        ELSE 'VALUE_022' END AS FIELD_2 
FROM  TABLE_A a
JOIN TABLE_B b
ON a.FIELD_X = b.FIELD_Y
GROUP BY A.FIELD_1, B.FIELD_2

CASE / WHEN条件下的TSQL聚合函数

3 个答案: