使用 case when 语句覆盖/更新 proc sql 中的 af 变量值

问题描述

我想将变量从旧"数据集左连接到新"数据集.UFORM 变量的值为 25 或 ..如果左连接给了我.的值，我想用值0替换它.我不能在下面的sql语句中更新UFORM变量的值而不是制作UFORM2变量吗?

I want to left join a variable from an "old" dataset to a "new" dataset.The UFORM variable has the values 25 or .. If the left join gives me the value of ., I want to replace it with the value 0. Can't I update the value of the UFORM-variable in the following sql statement in stead of making the UFORM2 variable?

下面的语句有效，但我宁愿不使用 UFORM2 变量.

The statement below works, but I'd rather not make the UFORM2-variable.

proc sql;
   create table new as
   select X.*, Z.UFORM , case when Z.UFORM eq . then 0 else Z.UFORM end as UFORM2
   from old X
   left join info Z
   on X.value1 = Z.value1
   and X.value2 = Z.value2;
quit;

推荐答案

这是您想要的吗?

proc sql;
   create table new as
   select X.*, coalesce(Z.UFORM, 0) as UFROM
   from old X left join
        info Z
        on X.value1 = Z.value1 and
           X.value2 = Z.value2;
quit;

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