請教SQL的一個語句

SAS裏的一段程序
Proc SQL NOPRINT;
select trim(left(put(count(name),8.))) into : trt1 - : trt3
From two
Group by department;
QUIT;

請問trim(left(put(count(name),8.))) 這段話裏每個關鍵字的作用是什麽？



proc sql noprint;
select compress(name)||'='|| trim(left(substr(name,3)))|| '_'||'MN'
into :mnlist
separated by ‘ ‘
from sashelp.vcolumn
where libname='PLAN' and memname='HDATA' and type=’num’ and name not in
(‘V1PATID’);
QUIT；

請問compress(name)||'='|| trim(left(substr(name,3)))|| '_'||'MN' 這段話的作用（每個關鍵字）是什麽。