好清楚的codes！！就是我想要的结果！围观大牛

多谢！

我还有一个问题想请教，如果我选择的下标变量y里有重复值，比如说y是1，3，6，6，最后通过proc sql产生的selecteddata里只有x1,x3,x6，第二个重复的x6就没有了。请问我该如何调整，才能显示所有x变量？大概我搜索的关键词不对，在网上也没有找合适的资料。谢谢指点！

First Proc SQL is fine. It selected all the columns as you can see in the log, but there can't be duplicate column names in a SAS data set, so duplicates were not selected in the second SQL. Here is a solution that might be close to what you want.

SAS LOG
6977   proc sql noprint;
6978   select selectedindex into: selectedindex separated by ','
6979   from index;
6980   %put &selectedindex;
x1,x3,x4,x4,x6,x6,x6
6981   create table selecteddata as
6982   select &selectedindex
6983   from data;
WARNING: Variable x4 already exists on file WORK.SELECTEDDATA.
WARNING: Variable x6 already exists on file WORK.SELECTEDDATA.
WARNING: Variable x6 already exists on file WORK.SELECTEDDATA.
NOTE: Table WORK.SELECTEDDATA created, with 10 rows and 4 columns.
6984   quit;

NEW CODE
data data;
input   x1 x2 x3 x4 x5 x6 x7 x8 x9 x10;
datalines;
2  3   5   6   9  9  5   5   4    1
2  2   4   7   6  3  5   2   4    11
1  6   8   2   1  2  9   6   6    14
5  3   2   4   6  0  1   2   5     3
2  8   7   6   2  5  5   7   3    2
2  3   5   6   9  9  5   5   4    1
5  3   4   1   3  4  6   7   3    9
6  0   1   6   2  5  1   3   4    6
2  3   5   6   9  9  5   5   4    1
5   5  1   3   6  2  2   4    7   3
;
run;
data index;
input index;
datalines;
1
3
6
4
6
4
6
;
run;
data index;
set index;
order+1;
run;
proc sort data=index ;
by index;
run;
data index;
set index;
by index;
selectedindex=compress('x'||index);
if first.index then count=1;
else count+1;
run;

data index;
set index;
length sql $30;
if count=1 then sql=selectedindex;
else sql=selectedindex||' as '||compress(selectedindex||'_'||count);
run;
proc sql noprint;
select sql into: selectedindex separated by ','
from index
order by order;
%put &selectedindex;
create table selecteddata as
select &selectedindex
from data;
quit;