sas

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Original

English

🇨🇳

Translation

Chinese

SAS Language

SAS语言

Write idiomatic, production-quality SAS code. This skill covers the SAS language itself, independent of any framework.

编写符合规范、可用于生产环境的SAS代码。本技能仅涵盖SAS语言本身，与任何框架无关。

Scope

适用范围

DATA step programming (SET/MERGE/BY, RETAIN, arrays, DO loops, hash objects, first./last. processing)
PROC SQL (joins, subqueries, views, pass-through with CONNECT TO)
Macro language (%macro/%mend, macro variables, %local/%global, conditional %IF logic, quoting functions %STR/%NRSTR/%BQUOTE, CALL SYMPUTX)
Common PROCs: SORT, MEANS/SUMMARY, FREQ, TRANSPOSE, REPORT, PRINT, CONTENTS, DATASETS, FORMAT, IMPORT/EXPORT
Formats and informats (user-defined via PROC FORMAT, picture formats)
ODS output (HTML, PDF, RTF, Excel, OUTPUT destination)
File I/O: LIBNAME, FILENAME, INFILE/INPUT, FILE/PUT

DATA step编程（SET/MERGE/BY、RETAIN、数组、DO循环、哈希对象、first./last.处理）
PROC SQL（连接、子查询、视图、使用CONNECT TO的直通查询）
宏语言（%macro/%mend、宏变量、%local/%global、条件%IF逻辑、引用函数%STR/%NRSTR/%BQUOTE、CALL SYMPUTX）
常用PROC过程：SORT、MEANS/SUMMARY、FREQ、TRANSPOSE、REPORT、PRINT、CONTENTS、DATASETS、FORMAT、IMPORT/EXPORT
格式与输入格式（通过PROC FORMAT自定义、图片格式）
ODS输出（HTML、PDF、RTF、Excel、OUTPUT目标）
文件I/O：LIBNAME、FILENAME、INFILE/INPUT、FILE/PUT

Non-negotiable: no WARNINGs

不可妥协：无WARNING信息

Generated SAS code must run cleanly — zero WARNINGs (and zero ERRORs) in the log. Treat every

WARNING:

as a defect: uninitialized variables, implicit type conversions, truncation notes that should be warnings, "no observations", unresolved macro references, etc. If a warning is truly unavoidable, suppress it deliberately (e.g. an explicit option) and comment why. Likewise avoid superfluous NOTEs where reasonable.

生成的SAS代码必须能干净运行——日志中零WARNING（且零ERROR）。将每一条

WARNING:

视为缺陷：未初始化变量、隐式类型转换、应作为警告的截断提示、“无观测值”、未解析的宏引用等。若警告确实无法避免，需主动抑制（例如使用显式选项）并注释原因。同样，在合理情况下避免多余的NOTE信息。

Style rules

风格规则

These follow the @sasjs/core coding standards — apply them to all SAS code:

One statement per line; indentation = 2 spaces, no tabs, no trailing whitespace
Lines no longer than 80 characters; unix (LF) line endings; UTF-8
Avoid non-ASCII / special characters entirely — maximum compatibility across SAS installations and encodings
Always end steps with
```
run;
```
; for
```
proc sql
```
(and CAS-connected procs)
```
quit;
```
is essential to avoid
```
WARNING: You cannot disconnect or terminate session ...
```
on Viya
All dataset references must be 2-level (
```
work.blah
```
, not
```
blah
```
) — protects against
```
DATASTMTCHK=ALLKEYWORDS
```
and an active
```
USER
```
library
Explicit
```
length
```
/
```
attrib
```
for character variables rather than relying on defaults (avoids implicit length=8 truncation)
Use literal suffixes for clarity (
```
'01JAN2020'd
```
,
```
'12:30't
```
)
Prefer
```
proc sort
```
with
```
nodupkey
```
over manual dedup logic
Macros:
- Define with parentheses, even with no parameters:
```
%macro x();
```
  not
```
%macro x;
```
- Closing
```
%mend;
```
  must repeat the macro name
- Macro calls are not terminated with a semicolon:
```
%my_macro()
```
  not
```
%my_macro();
```
- Mandatory parameters positional; optional parameters keyword (
```
var=
```
  ) style
- Macro names lowercase, verb-noun convention
- Macro variables without trailing dot (
```
&var
```
  not
```
&var.
```
  ) unless needed to prevent incorrect resolution
- ALL macro variables must be
```
%local
```
  unless deliberately global (globals should use an application prefix to avoid collisions); use
```
call symputx
```
  (not
```
symput
```
  ) in DATA steps
- Comment with
```
/* */
```
  inside macros (asterisk comments are compiled into the macro)
- Guard macro logic with
```
%length(&var)=0
```
  checks rather than
```
&var=
```
  (empty comparisons are unsafe)
Avoid naming collisions: use
```
%sysfunc
```
-/
```
&syslast
```
-based work tables (e.g.
```
data &output; set &syslast; run;
```
) rather than hard-coded names

以下遵循@sasjs/core编码标准——适用于所有SAS代码：

一行一条语句；缩进为2个空格，不使用制表符，无尾随空格
行长度不超过80字符；使用Unix（LF）换行符；UTF-8编码
完全避免非ASCII/特殊字符——确保在不同SAS安装环境和编码下的最大兼容性
所有步骤必须以
```
run;
```
结尾；对于
```
proc sql
```
（及连接CAS的过程），必须使用
```
quit;
```
以避免Viya上出现
```
WARNING: You cannot disconnect or terminate session ...
```
警告
所有数据集引用必须使用两级命名（
```
work.blah
```
，而非
```
blah
```
）——防止
```
DATASTMTCHK=ALLKEYWORDS
```
和活跃
```
USER
```
库导致的问题
字符变量需显式定义
```
length
```
/
```
attrib
```
，而非依赖默认设置（避免隐式长度为8的截断问题）
使用字面量后缀增强清晰度（
```
'01JAN2020'd
```
、
```
'12:30't
```
）
优先使用带
```
nodupkey
```
的
```
proc sort
```
而非手动去重逻辑
宏相关规则：
- 定义宏时需加括号，即使无参数：
```
%macro x();
```
  而非
```
%macro x;
```
- 结束宏的
```
%mend;
```
  必须重复宏名称
- 宏调用无需以分号结尾：
```
%my_macro()
```
  而非
```
%my_macro();
```
- 必填参数使用位置式；可选参数使用关键字（
```
var=
```
  ）风格
- 宏名称使用小写，遵循“动词-名词”命名规范
- 宏变量无需尾随点号（
```
&var
```
  而非
```
&var.
```
  ），除非需要避免解析错误
- 所有宏变量必须定义为
```
%local
```
  ，除非特意设为全局变量（全局变量应使用应用前缀以避免冲突）；在DATA step中使用
```
call symputx
```
  （而非
```
symput
```
  ）
- 宏内部使用
```
/* */
```
  注释（星号注释会被编译到宏中）
- 使用
```
%length(&var)=0
```
  检查宏逻辑，而非
```
&var=
```
  （空值比较不安全）
避免命名冲突：使用基于
```
%sysfunc
```
/
```
&syslast
```
的临时表（例如
```
data &output; set &syslast; run;
```
）而非硬编码名称

Portability awareness

可移植性注意事项

Note when code differs between SAS 9.4 and Viya (e.g. CAS actions vs procs,
```
proc casutil
```
for sashdat loading, no X command on locked-down servers)
Avoid hard-coded physical paths and engine-specific options unless asked

注意SAS 9.4与Viya之间的代码差异（例如CAS动作与过程、使用
```
proc casutil
```
加载sashdat文件、锁定服务器上无X命令）
除非特别要求，否则避免硬编码物理路径和引擎特定选项

Common pitfalls to flag when reviewing

代码审查时需标记的常见陷阱

Unintended many-to-many MERGEs
Automatic variable
```
_ERROR_
```
/ implicit RETAIN surprises
Macro timing issues: referencing
```
&macrovar
```
before it exists,
```
%if
```
evaluating data-step variables (use
```
if
```
/
```
symget
```
instead)

Automatic macro variables (

&syscc

&syswarningtext

&syserrortext

&sysdate

&sysuserid

, etc.) are READ-ONLY — attempting to overwrite them (e.g.

%let syswarningtext=;

call symput('syscc',...)

) raises

ERROR: Unable to assign value to a macro variable that is read only

(or similar). Never try to "clear" them.

Truncation from implicit length=8 on first assignment
```
proc sql
```
cartesian product warnings

非预期的多对多MERGE操作
自动变量
```
_ERROR_
```
/隐式RETAIN带来的意外问题
宏时机问题：在
```
&macrovar
```
存在前引用它、
```
%if
```
评估DATA step变量（应使用
```
if
```
/
```
symget
```
替代）

自动宏变量（

&syscc

、

&syswarningtext

、

&syserrortext

、

&sysdate

、

&sysuserid

等）为只读——尝试覆盖它们（例如

%let syswarningtext=;

或

call symput('syscc',...)

）会触发

ERROR: Unable to assign value to a macro variable that is read only

（或类似错误）。切勿尝试“清除”这些变量。

首次赋值时因隐式长度为8导致的截断问题
```
proc sql
```
笛卡尔积警告