azure - 在 Azure 流分析 SAQL 中满足条件时的默认字段值

Question

我需要根据文档中可用的另一个字段的值来设置一个字段的值。

以下是我尝试获取要求的 SAQL。

WITH INPUT01 AS (
    SELECT
        input.id AS ID,
        ROUND(input.sig,5) AS SIG,
        input.dtcTriggeredDateTime.dateTime.time AS TIME,
        input.Description as DESC
        FROM [inputsignals] as input
    WHERE GetArrayLength(input.abc) =0 AND (input.Description = 'xyz' OR input.Description = 'pqr')

SELECT 
    ID,
    SIG,
    TIME,
    001 AS NUMID 
INTO [cosmosDB]
FROM INPUT01
WHERE DESC = 'abc'

SELECT 
    ID,
    SIG,
    TIME,
    002 AS NUMID 
INTO [cosmosDB]
FROM INPUT01
WHERE DESC = 'pqr'

如果 DESC 是abc那么NUMID应该是001并且如果 DESC 是pqr那么NUMID应该是002。

除了单独编写最后两个选择语句之外，还有什么选项可以在单个 SELECT 查询中编写它，如下所示？

SELECT 
    ID,
    SIG,
    TIME,
    001 AS NUMID  (If DESC = abc)
    002 AS NUMID  (If DESC = pqr)
INTO [cosmosDB]
FROM INPUT01

Answer 1

请在 SA SQL 中使用CASE...WHEN...运算符：

SELECT
    CASE
      WHEN DESC = 'abc' THEN 001
      WHEN DESC = 'pqr' THEN 002 
   END as NUMID  
FROM INPUT01