SQL - 基于计算字段的计算字段?

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问题描述

我有两列连接 A&B，这样做是为了找出客户 ID.然后我需要在该计算字段上做一个 case 语句.可以一次性完成吗?

Hi I have two columns which I concatenate A&B, this is done to figure out the customer ID.I need to then do a case statement on that calculated field.Can it be done in one go?

Column A
Column B
Column C = Column A & Column B
Column D = Case When (column C) = 001-002 then XXXX

D 列不起作用.问题是，如果 C 列是计算字段，那么我可以在单个查询中计算出 C 列以给出 D 列吗?

Column D is not working. The question is if column C is a calculated field, can I then calculate off column C to give column D, in a single query?

谢谢

推荐答案

你应该这样做...因为计算列不会帮助进一步计算

You should do it in this way...as calculated columns is not going to help in further calculation

Column A
Column B
Column C = Column A & Column B
Column D = Case When (Column A & Column B) = 001-002 then XXXX

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