表链接proc sql

朱世武的书<SAS 编程技术>的例子很详细,现在想想基本上涵盖了一些论坛上的问题.

/*21.1.1 简单连接*/proc sql;select * from resdat.china, resdat.usa;quit/*21.1.3 内部连接*/proc sql;select * from resdat.china, resdat.usawhere china.level=usa.level;quit;/*21.1.3.1 使用表的别名*/proc sql;select * from resdat.china as a, resdat.usa as bwhere a.level=b.level;quit;/*21.1.3.2 使用别名进行表的自我连接*/proc sql;select * from resdat.china a, resdat.china bwhere a.level<b.level;quit;/*21.1.3.3 设定连接输出的排列顺序*/proc sql;select * from resdat.china a, resdat.china bwhere a.level<b.levelorder by a.level desc;quit; /*21.1.6 缺失值对连接的影响*//* 程序一 */proc sql;   title ' Table A and B Joined';   select a.obs 'A-OBS', a.stkcd, b.obs 'B-OBS', b.stkcd      from a, b      where a.stkcd= b.stkcd;/* 程序二 */proc sql;   title ' Table Three and Four Joined';   select Three.Obs '3-OBS', Three.Fdcd, Four.Obs '4-OBS', Four.Fdcd      from Three, Four      where Three.fdcd= Four.fdcd and             three.fdcd is not missing;/* 21.1.7 从多于两个表的数据集中查询数据 */proc sql outobs=3;select a.stkcd,b.lstknm,c.clprfrom resdat.sampstk a,resdat.lstkinfo b,resdat.qttndist cwhere a.stkcd=b.stkcd and  b.stkcd=c.stkcd and a.stkcd=c.stkcd;quit;         /* 21.1.8.1 左外部连接 */proc sql;select * from resdat.china a left join resdat.usa bon a.level=b.level;quit;/* 21.1.8.2 右外部连接 */proc sql;select * from resdat.china a right join resdat.usa bon a.level=b.level;quit;/*21.1.8.3 完全外部连接*/proc sql;select * from resdat.china a full join resdat.usa bon a.level=b.level;quit;/*21.1.9.1 与简单连接功能相同的Cross连接 */proc sql;select * from resdat.china cross join resdat.usa;quit;/*21.1.9.2 包含所有行的Union连接  */proc sql;select * from resdat.china union join resdat.usa;quit;/*21.1.9.3使用自动匹配连接的Natural连接*/proc sql;select * from resdat.china union join resdat.usa;quit;/* 21.1.10 连接使用COALESCE函数 */Proc sql;select a.level,a.china,coalesce(b.level,a.level),coalesce(b.usa,a.china)as usafrom resdat.china a full join resdat.usa bon a.level=b.level;quit;    /* 21.2.1 所有行匹配无重复值的情况 */data merge1;   merge a b;   by code;run;proc print data=merge1 noobs;   title 'Table MERGE1';run;        proc sql;   title 'Table MERGE1';   select a.code, a.manager, b.Assitant      from a, b      where a.code=b.code;quit;/* 21.2.2 部分行匹配无重复值的情况 *//* 程序一 */data merge2;   merge a b;   by code;run;proc print data=merge2 noobs;   title 'Table MERGE2';run;/* 程序二*/proc sql;select code,a.manager,b.assistant from a natural full join b;quit;/* 21.2.3有重复值的情况 *//*程序一*/data merge3;   merge a b;   by code;run;proc print data=merge3 noobs;   title 'Table MERGE3';run;/* 程序二*/Proc sql;Title 'Table Merge3';Select a.code, a.manager, b.assistant From a full join b On a.code=b.code;quit;    /* 21.3.1 产生单个值的子查询 */Proc sql;Title 'Which Manager has the same code as Assistant Chen';Select *From aWhere code eq (select code from b where assistant='Chen');Quit；/* 21.3.2 产生多个值的子查询 */Proc sql;select stkcd,lstknm,lstdt from resdat.lstkinfowhere stkcd in (select stkcd from resdat.sampstk);quit; /* 21.3.3 混合子查询 */proc sql;select stkcd,yrret from resdat.yrret a       where (select stktype from resdat.lstkinfo b                     where a.stkcd=b.stkcd)='A' and '1jan2005'd<=date<='31dec2005'd;quit;/* 21.3.5 子查询的多重嵌套 */Proc sql;select stkcd,yrret from resdat.yrret a       where stkcd in (select stkcd from resdat.sampstk b                          where stkcd in(select stkcd from resdat.lstkinfo c                        where c.stktype='A')) and '1jan2005'd<=date<='31dec2005'd;quit;/*21.3.6 在JOIN连接中使用子查询*/proc sql;select a.id,b.id,sqrt((a.x-b.x)**2+(a.y-b.y)**2)as dist from point a,point b       where a.id lt b.id and             calculated dist=(select min(sqrt((c.x-d.x)**2+(c.y-d.y)**2))                                 from point c,point d         where c.id lt d.id);quit;/*21.5.2 由多个查询产生非重复观测 (UNION算符)*//*程序一*/proc sql;   title 'A UNION B';   select * from A   union   select * from B;quit;/* 程序二 */proc sql;   title 'A UNION ALL B';   select * from A   union all   select * from B;quit;/*21.5.3 产生只属于第一个查询的观测(EXCEPT算符)*//*程序一*/proc sql;   title 'A EXCEPT B';   select * from A   except   select * from B;quit;/*程序二*/proc sql;   title 'A EXCEPT ALL B';   select * from A   except all   select * from B;/*21.5.4 从多个查询中产生公共部分 (INTERSECT算符)*/proc sql;   title 'A INTERSECT B';   select * from A   intersect   select * from B;/*21.5.5 直接连接查询结果 (OUTER UNION算符)*//*程序一*/proc sql;   title 'A OUTER UNION B';   select * from A   outer union   select * from B; /*程序二*/proc sql;   title 'A OUTER UNION CORR B';   select * from A   outer union corr   select * from B;/* 21.5.6 特殊的查询合并方式 */proc sql;   title 'A EXCLUSIVE UNION B';   (select * from A         except         select * from B)   union   (select * from B         except         select * from A);