将SQL IIF转换为Redshift

Question

我有sql server脚本,我需要转换为Redshift

这是我遇到问题的代码的一部分

IIF(smf.channelid IS NULL, 0, 1) AS IsFeatureKey,
IIF(codeLabel.CslId > 0, 1, 0) AS IsCslCode,
IIF(codeLabel.LearnId > 0, 1, 0) AS IsLearnCode,
IIF(codeLabel.PMId > 0, 1, 0) AS IsPMCode,
IIF(codeLabel.UpSell > 0, 1, 0) AS IsUpSell

我怎样才能正确地将它转换为Redshift？

Answer 1

IIF只是用于CASE表达的语法糖(这种行为在文档中提到).您的代码与以下内容相同:

CASE WHEN smf.channelid IS NULL THEN 0 ELSE 1 END AS IsFeatureKey,
CASE WHEN codeLabel.CslId > 0 THEN 1 ELSE 0 END AS IsCslCode,
CASE WHEN codeLabel.LearnId > 0 THEN 1 ELSE 0 END AS IsLearnCode,
CASE WHEN codeLabel.PMId > 0 THEN 1 ELSE 0 END AS IsPMCode,
CASE WHEN codeLabel.UpSell > 0 THEN 1 ELSE 0 END AS IsUpSell