调用执行在 SAS 中不起作用

Question

data numbers;
  input num;
  datalines;
  3
  1
  3
  ;
run;

%macro temp(num);
  proc sql noprint;
    select count(*) into :count from numbers;
  quit;
  %if (&num eq &count) %then 
    %put Match Found;
  %else 
    %put No Match Found;
  %symdel count;
%mend;

data _NULL_;
  set numbers;
  call execute('%temp('||num||')');
run;

为什么这个代码显示错误，尽管一切都是正确的。 我正在检查数据集编号中的值以查找之间的匹配 可变数字的总计数（仅供练习） 在检查了我的条件后，我使用 proc SQL 得到了计数 我正在删除 count 宏变量。后 执行 SAS 给出错误消息的原因。请解释什么 确实发生在这段代码中。

LOG-----when I execute the last data step--------->

    6188   data _NULL_;
    6189   set numbers;
    6190   call execute('%temp('||num||')');
    6191   run;

    NOTE: Numeric values have been converted to character values at the places given by:
                (Line):(Column).
                6190:24
    Match Found
    WARNING: Apparent symbolic reference COUNT not resolved.
    ERROR: A character operand was found in the %EVAL function or %IF condition where a numeric
                 operand is required. The condition was: &num eq &count
    ERROR: The macro TEMP will stop executing.
    WARNING: Apparent symbolic reference COUNT not resolved.
    ERROR: A character operand was found in the %EVAL function or %IF condition where a numeric
                 operand is required. The condition was: &num eq &count
    ERROR: The macro TEMP will stop executing.
    NOTE: The SAS System stopped processing this step because of errors.
    NOTE: There were 3 observations read from the data set WORK.NUMBERS.
    NOTE: DATA statement used (Total process time):
                real time           0.00 seconds
                cpu time            0.00 seconds


    NOTE: CALL EXECUTE generated line.
    1     + proc sql;
    1     +           select count(*) into :count from numbers;
    1     +                                                     quit;
    NOTE: PROCEDURE SQL used (Total process time):
                real time           0.09 seconds
                cpu time            0.00 seconds


    2     + proc sql;
    2     +           select count(*) into :count from numbers;
    2     +                                                     quit;
    NOTE: PROCEDURE SQL used (Total process time):
                real time           0.15 seconds
                cpu time            0.01 seconds


    3     + proc sql;
    3     +           select count(*) into :count from numbers;
    3     +                                                     quit;
    NOTE: PROCEDURE SQL used (Total process time):
                real time           0.15 seconds
                cpu time            0.01 seconds

Answer 1

当 CALL EXECUTE() 语句运行时，代码被压入堆栈。由于您没有使用任何宏引用宏实际上正在运行，并且生成的代码被推入堆栈。因此 %IF 语句在 SELECT 语句运行之前运行。您可以使用 %NRSTR() 来延迟此操作，以便将宏调用推入堆栈。

call execute(cats('%nrstr(%temp)(',num,')'));

或者只是避免 CALL EXECUTE 并使用 PUT 语句将代码写入您可以 %INCLUDE 的文件。

filename code temp;
data _null_;
  set numbers;
  file code ;
  put '%temp(' num ')' ;
run;
%include code / source2 ;

Answer 2

引用documentation page 的调用执行：

注意：因为宏引用立即执行并且 SAS 语句直到步边界之后才会执行，您不能使用 CALL EXECUTE 调用包含宏引用的宏 由 CALL SYMPUT 在该宏中创建的变量。

我认为您在这里尝试做的基本上是相同的事情，只是在您的宏中使用proc sql 的select into 而不是call symput。

解决此限制的一种方法是使用dosubl 函数。您可以使用它来创建一个函数样式的宏，然后您可以通过call execute 生成的%put 语句运行该宏：

data numbers;
input num;
datalines;
3
1
3
;
run;

%symdel COUNT;

%macro temp(num);
%sysfunc(dosubl(proc sql noprint;
select count(*) into :count from numbers;
quit;))
   %if &num eq &count %then 
        %put Match Found;
    %else 
        %put No Match Found;
%mend;

data _NULL_;
set numbers;
count = symget('Count');
put "Before call execute " _n_= count=;
call execute('%put rc=%temp('||num||');');
count = symget('Count');
put "After call execute " _n_= count=;
run;

或者，您可以将dosubl 调用放在数据步骤中，而不是宏定义中：

%symdel COUNT;

%macro temp(num);
proc sql noprint;
select count(*) into :count from numbers;
quit;
   %if &num eq &count %then 
        %put Match Found;
    %else 
        %put No Match Found;
%mend;


data _NULL_;
set numbers;
count = symget('Count');
put "Before call execute " _n_= count=;
rc = dosubl('%temp('||num||')');
count = symget('Count');
put "After call execute " _n_= count=;
run;