如何将数据添加到不同组的SAS表中？

主键是car、model和date，我必须用前面的数据填充空白字段，但它的主键是car和model。 例如：

 Row    Car       Model   Date   Sec    Door    Colour
 1      Ford      Focus   2002   1      5       blue
 2      Ford      Focus   2002   2      5       blue
 3      Ford      Focus   2002   3      5       blue
 4      Ford      Focus   2002   4      5       blue
 5      Ford      kuga    2004   5      5       blue
 6      Ford      kuga    2004   1      5   
 7      Ford      kuga    2004   2      5   
 8      Ford      Mondeo  2004   3      5       red
 9      Ford      Mondeo  2004   4      4       red
10      Ford      Mondeo  2004   5              red
11      Ford      Mondeo  2004   6              red
12      Ford      Mondeo  2004   7      4       red
13      Mercedes  Benz    2010   1      3   
14      Mercedes  Benz    2010   1      3       white
15      Mercedes  Benz    2010   1      5       Yellow
16      Mercedes  190E    2011   1              red
17      Mercedes  190E    2012   1      6   

表的最终输出是

输出：

 Row    Car       Model   Date   Sec    Door    Colour
 1    Ford       Focus    2002   1      5       blue
 2    Ford       Focus    2002   2      5       blue
 3    Ford       Focus    2002   3      5       blue
 4    Ford       Focus    2002   4      5       blue
 5    Ford       kuga     2004   5      5       blue
 6    Ford       kuga     2004   1      5       blue
 7    Ford       kuga     2004   2      5       blue
 8    Ford       Mondeo   2004   3      5       red
 9    Ford       Mondeo   2004   4      4       red
10    Ford       Mondeo   2004   5      4       red
11    Ford       Mondeo   2004   6      4       red
12    Ford       Mondeo   2004   7      4       red
13    Mercedes   Benz     2010   1      3       red
14    Mercedes   Benz     2010   1      3       white
15    Mercedes   Benz     2010   1      5       Yellow
16    Mercedes   190E     2011   1      5       red
17    Mercedes   190E     2012   1      6       red

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怎么做的？谢谢

更新技巧将产生您显示的输出

data cars;
   retain dummyby 1;
   infile cards firstobs=2;
   input row car $ model $ date sex door colour $;
   cards;
Row    Car       Model   Date   Sec    Door    Colour
 1      Ford      Focus   2002   1      5       blue
 2      Ford      Focus   2002   2      5       blue
 3      Ford      Focus   2002   3      5       blue
 4      Ford      Focus   2002   4      5       blue
 5      Ford      kuga    2004   5      5       blue
 6      Ford      kuga    2004   1      5       .
 7      Ford      kuga    2004   2      5       .
 8      Ford      Mondeo  2004   3      5       red
 9      Ford      Mondeo  2004   4      4       red
10      Ford      Mondeo  2004   5      .       red
11      Ford      Mondeo  2004   6      .       red
12      Ford      Mondeo  2004   7      4       red
13      Mercedes  Benz    2010   1      3       .
14      Mercedes  Benz    2010   1      3       white
15      Mercedes  Benz    2010   1      5       Yellow
16      Mercedes  190E    2011   1      .       red
17      Mercedes  190E    2012   1      6       .
;;;;
   run;
data locf;
   update cars(obs=0) cars;
   by dummyby; *Use BY CAR; to LOCF for each car.;
   output;
   drop dummyby;
   run;
proc print;
   run;

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