Given the following code:
proc print data=SASHELP.CLASS(firstobs=5 obs=15);
where Sex=’M’;
run;
How many observations will be displayed?
A. 11
B. 15
C. 10 or fewer
D. 11 or fewer
注解：首先只有5-11行中的数据才会被打印出来，所以最多能出现11条数据，其次这些数据还需要满足Sex为M。FIRSTOBS和OBS参考SAS Base (5)。
The SAS data set WORK.ONE contains a numeric variable named Num and a character variable named Char:
| Num | Char |
| 1 | 23 |
| 2 | 23 |
| 1 | 77 |
The following SAS program is submitted:
proc print data=WORK.ONE;
where Num=’1′;
run;
What is output?
A.
| Obs | Num | Char |
| 1 | 1 | 23 |
B.
| Obs | Num | Char |
| 1 | 1 | 23 |
| 3 | 1 | 77 |
C.
| Obs | Num | Char |
| 1 | 1 | 23 |
| 2 | 2 | 23 |
| 3 | 1 | 77 |
D. No output is generated.
Check Answer注解：数值型无法和字符型进行逻辑运算（例如：比大小），并且WHERE statement不会自动将字符型转换成数值型。Log中会显示”ERROR: WHERE clause operator requires compatible variables.”。