Proc SQL是否会导致在宏变量INTO中选择的值被宏引用

Question

考虑这个示例，其中所选值具有特殊的宏字符&和%影响分辨率。CCD_ 1用于屏蔽字符。

data have;
id=1; s='A&B %now';
proc sql noprint;
select s into :myvar from have where id=1;
%put &=myvar;
%put &myvar;
%let myvar = %superq(myvar);  /* macro quote the special symbols & and % */
%put &=myvar;
------------------- LOG -------------------
53   proc sql noprint;
54     select s into :myvar from have where id=1;
55
56   %put &=myvar;
WARNING: Apparent symbolic reference B not resolved.
WARNING: Apparent invocation of macro NOW not resolved.
MYVAR=A&B %now
57   %put &myvar;
WARNING: Apparent symbolic reference B not resolved.
WARNING: Apparent invocation of macro NOW not resolved.
A&B %now
58
59   %let myvar = %superq(myvar);  /* macro quote the special symbols & and % */
60
61   %put &=myvar;
MYVAR=A&B %now

是否存在强制宏引用所选值的SELECT <expression> INTO :<symbol>语法？

Answer 1

否。

在SELECT之后添加%LET语句。

proc sql noprint;
select s into :myvar from have where id=1;
%let myvar=%superq(myvar);

或者添加实际的引号字符。

proc sql noprint;
select quote(trim(s),"'") into :myvar from have where id=1;