取前N条记录

data temp;
set A;
if n<=n;
run;
方法一：
data temp1;
set sashelp.air(firstobs=n obs=n/obs=n);
run;
/firstobs.n < obs.n/
方法二：
proc sql;
create table temp2 as
select * from sashelp.air(firstobs=n obs=n/obs=n);
quit;
/firstobs.n < obs.n/
方法三：
proc sql inobs=n;
create table temp3 as
select * from sashelp.air;
quit;
方法四：
proc sql outobs=n;
create table temp4 as
select * from sashelp.air;
quit;