带有 WHERE 子句的 SQL 查询 CASE 语句

Question

我构建了以下使用多条件 CASE 语句的查询。这是使用多条件 CASE 语句的正确/最佳方法吗？

只要我不在 where 中引用 CASE 语句，它就可以工作。我收到“无效的列名称‘场景’。”

如何在查询的 WHERE 部分中引用 ScenarioA？

select 
    TPID
    ,(CASE WHEN 
        ([AOppty] > 0) and ([Entitlements] = 0) and ([B Agreement] = 0 and [C Agreement] = 0)
    THEN 1 ELSE 0 END) as ScenarioA
from RulesEngine R
--where ScenarioA = 1

Answer 1

SQL Server 允许您为此使用公共(public)表表达式:

WITH
    Rules (TPID, ScenarioA)
AS (
    SELECT 
        TPID
    ,   (CASE WHEN 
            ([AOppty] > 0) AND ([Entitlements] = 0) AND ([B Agreement] = 0 and [C Agreement] = 0)
            THEN 1 ELSE 0 END
        ) AS ScenarioA
)
SELECT
    TPID, ScenarioA
WHERE
    ScenarioA = ...