71. A SAS program is submitted and the following is written to the SAS log:
15 %let col1 =dept; 16 %let data = company; 17 18 proc sql; 19 select * 20
from &data, employee 21
where &data.&col1 = employee.name; 22 quit; ERROR : The following columns
were not
found in the contributing tables: companydept. What caused the error?
A.The data set COMPANY does not contain the variable DEPT.
B.There should be a second period after &DATA in the WHERE clause.
C.There should be two ampersands in front of DATA in the WHERE clause.
D.There should be two ampersands in front of COL1 in the WHERE clause.
答案是B。&是TOKEN，一个PERIOD就应该可以了吧？为什么还是要两个？
