按照这个公司，用SQL按照时间序列统计，看看是否是小于20 然后就delete

你是说要一个一个公司来？ 主要是有非常多的公司，输入一个个公司的名字不大现实。
数据很大

或者有办法能删除公司名字出现次数少于20次的，应该也可以。
就是不知道怎么操作

这个是删除公司出现次数小于2的，看一下：）


data x;
input company$ time;
cards;
001 2
002 4
002 5
002 8
;run;
proc sql;
select * from x  group by company having  count(company)>2;quit;

proc sort data=your_data;
by companies;
proc means data = your_data noprint;
output out=after_deletion(drop = _type_ _freq_ where=(Num_of_price>=20)
             n(stock_series) =Num_of_prices;
by your_companies;
run;

The data of "after_deletion" contains the company names having number of observations >=20.

Then merge your original data with the data of "after_deletion";  The final output will only contain the available companies in "after_deletion".

data final;
   merge your_data(in = yours)
               after_deletion( in = after);
if yours and after;
by your_companies;
run;