SAS宏使用循环反规范化

Question

我想知道我是否可以在Macro Loop中做到这一点。

例如，这是tableA

ID  --  Fruit      --       Count
1       Banana               1
1       Strawberry           2
1       Apple                3
1       Blueberries          4
2       Apple                1
3       Strawberry           1
3       Apple                2  

我通常不使用SAS MACRO这样做

proc sql;
select ID,t2.fruit AS fruit1,
          t3.fruit AS fruit2,
          .
          .
          .
from core_table t1
LEFT JOIN TableA t2 on t2.id = t1.id AND t2.count=1 
LEFT JOIN TableA t3 on t3.id = t1.id AND t3.count=2
.
.
.
.

所以输出就像

ID Fruit1      Fruit2        Fruit3    Fruit4 
1  Banana      Strawberry    Apple     Blueberries          
2  Apple                
3  Strawberry  Apple  

基本上，输出会使变量标准化。所以我想我可以通过使用Do循环来完成此任务，我一直在谷歌搜索，但是我不知道该怎么做。

谢谢

Answer 1

No need for a macro for something like that. Just use PROC TRANSPOSE.

First let's convert your listing into an actual SAS dataset so we have something to test with.

data have ;
  input id fruit :$20. count;
cards;
1       Banana               1
1       Strawberry           2
1       Apple                3
1       Blueberries          4
2       Apple                1
3       Strawberry           1
3       Apple                2  
;

Here is the PROC TRANSPOSE code to convert it.

proc transpose data=have out=want prefix=Fruit;
 by id;
 var fruit;
 id count;
run;

Results:

Obs    id    _NAME_    Fruit1        Fruit2        Fruit3      Fruit4

 1      1    fruit     Banana        Strawberry    Apple     Blueberries
 2      2    fruit     Apple
 3      3    fruit     Strawberry    Apple