怎样计算sas数据集的行数？

shiyiming

回复lightening[code:8848uof3]proc sql noprint outobs=5;
     create table temp as
         select *
         from class;
quit;
[/code:8848uof3]

shiyiming

Thanks again, urchin,
Your link opens another window for me to learn SAS.

It works after I reviewed horse1's entry. I tried on a big dataset.
Thanks a lot, all of you.

[color=#4000FF:1xy0jay6]proc sql  outobs=10;       /* 如果要选 第 200 至 299 的记录呢？*/
   Create table work.temp as
select *
from sashelp.class
order by height desc;
quit; [/color:1xy0jay6]

只是感到奇怪，有些很简单的东西，SAS 处理起来变得复杂了。
.Net 好像可以  Select top 10 .... from table_Name;

FoxPro 可以 Select * from yourtable where  recno()<=10;

Select yourtable
Go Bottom
? recno()     * 显示所有记录, (包括已删除的)；

或：
Select * from yourtable
? _tally

shiyiming

那你可以在用SQL读入数据前做个flag, 然后在sql中用where语句

shiyiming

干吗放着强大的DATA STEP不用，老想着用SQL啊？在SAS里能不用SQL就不要用，执行效率巨低下！
[code:2kr92e4n]data class;
set sashelp.class(firstobs=2 obs=10);
run;[/code:2kr92e4n]
[code:2kr92e4n]proc sort data=sashelp.class(firstobs=2 obs=10) out=class;
by height descending;
run;[/code:2kr92e4n]
[code:2kr92e4n]proc sort data=sashelp.class out=class;
by height descending;
run;
data class;
set class(firstobs=2 obs=10);
run;[/code:2kr92e4n]

shiyiming

十分感谢。一些模糊概念变得清晰起来。

shiyiming

用select直接生成红变量就OK了
proc sql;
     create table temp as
    select count(*) into :totnum
    from sashelp.class;
quit;
put &totnum;

shiyiming

那个 Put 不好使呀。

shiyiming

%put &totnum;

shiyiming

是这样吗？
proc sql;
create table temp as
select count(*) into :totnum
from sashelp.class;
quit;

Data _null_;
%put &totnum=;
run;

Log screen 显示

WARNING: Apparent symbolic reference TOTNUM not resolved.

shiyiming

晕，还要手把手写的这么详细才行啊。你需要恶补SAS Programming I和II，还有SAS Macro这些教材啊。
不过前面不是特意写了，proc sql的效率暴差。如果原始数据集很大，这个过程将会是若干小时。用我之前写的方法，无论原始数据集多大，运行时间始终不超过5秒。
<!-- s:lol: --><img src="{SMILIES_PATH}/icon_lol.gif" alt=":lol:" title="Laughing" /><!-- s:lol: --> [code:1zggklsw]proc sql;
create table temp as
select count(*) into &#58;totnum
from sashelp&#46;class;
quit;
%put &amp;totnum; [/code:1zggklsw]