1

让我们假设我有一个文件 A 具有以下数据： 

A1.01  
A2.02  
A4.03   
A6.01

文件 B 具有以下数据： 

A2.02 xyshahaslsl  
A2.02 dkjhsldhsds  
A2.02 ewewhrewjws  
A4.03 wejwejwrewl  
A4.03 wejedededee  
A5.01 kdkgskhdgss  
A5.02 fljsdfjdfjd  
A5.03 sdjdhsdhsld  
A7.04 jhsdhskdhsd  
A7.07 dsjdhslkhds

如果它与第二个文件的记录的前两个字母数据匹配，则需要从文件B中删除文件A中存在的记录。

因此输出应如下所示： 

A5.01 kdkgskhdgss  
A5.02 fljsdfjdfjd  
A5.03 sdjdhsdhsld  
A7.04 jhsdhskdhsd  
A7.07 dsjdhslkhds

我的文件 A 有 400 条记录，文件 B 有 50 万条记录。我运行了一个 COBOL 程序，但运行时间过长。

cobol 程序逻辑如下：
这里我将包含 50 万条记录的文件作为 A。
将包含 400 条记录的文件作为文件 B。 

WORKING-STORAGE SECTION.                         
01 WS-RECORDS-WRITTEN    PIC 9(8) VALUE ZEROES.  
01 WS-RECORDS-DELETED    PIC 9(8) VALUE ZEROES.  
01 WS-INSERT-FILE-STATUS PIC X(2).               
01 WS-EOFA PIC A(1) VALUE 'N'.                   
01 WS-EOFB PIC A(1) VALUE 'N'.                   
01 WS-FLAG-FOUND PIC A(1) VALUE 'N'. 



PROCEDURE DIVISION.                                    
MAIN-PARA.                                             
     OPEN INPUT IFILEA                                 
     OPEN OUTPUT OFILE                                 
     PERFORM PARA0 THRU PARA0-EXIT UNTIL WS-EOFA = "Y" 
     CLOSE IFILEA                                      
     CLOSE OFILE                                       
     STOP RUN.                                         
     EXIT.                                             
PARA0.                                                 
     READ IFILEA                                       
     AT END MOVE "Y" TO WS-EOFA                        
     END-READ                                          
     IF WS-EOFA = "N"                                  
        OPEN INPUT IFILEB                              
       MOVE "N" TO WS-EOFB                             
       MOVE "N" TO WS-FLAG-FOUND                       
         PERFORM PARA1 THRU PARA1-EXIT UNTIL WS-EOFB = "Y"  
             OR WS-FLAG-FOUND = "Y"                         
         IF WS-FLAG-FOUND = "N"                             
            WRITE F2RECORD FROM F0RECORD                    
         END-IF                                             
        CLOSE IFILEB                                        
      END-IF.                                               
 PARA0-EXIT.                                                
      EXIT.                                                 
 PARA1.                                                     
      READ IFILEB                                           
      AT END MOVE "Y" TO WS-EOFB                            
      END-READ                                              
      IF OSS024S-TRACKING-ID = OSS024V-REC                  
* SKIP THE RECORD                                           
        MOVE "Y" TO WS-FLAG-FOUND                           
      END-IF.                                               
 PARA1-EXIT.                                                
      EXIT.
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1 回答 1

3

[为清楚起见，添加了示例文件控制、文件部分和所需的工作存储。
跟随弹跳球查看其他涉及的文件。引用的文件名用于我的测试。只是为了简洁起见]

FILE-CONTROL.
    SELECT FILE-A ASSIGN TO "Q30309414.EXC"
            ORGANIZATION IS LINE SEQUENTIAL
        FILE STATUS  IS FILE-A-STATUS.

FILE SECTION.
FD  FILE-A.        
01  FILE-A-REC.
    05 FILE-A-FIELD    PIC X(02).
    05 FILLER          PIC X(18).

WORKING-STORAGE SECTION.
01  FILE-A-STATUS            PIC X(02).
    88 EOF-A                 VALUE '10'.

MAINLINE.
    OPEN INPUT FILE-A.
    OPEN INPUT FILE-B.
    OPEN OUTPUT FILE-O.
    MOVE LOW-VALUES          TO FILE-A-REC.
    PERFORM READ-AND-FILTER 
      UNTIL EOF-B.
    CLOSE FILE-A.
    CLOSE FILE-B.
    CLOSE FILE-O.
    STOP RUN.

READ-AND-FILTER.
    READ FILE-B AT END MOVE HIGH-VALUES TO FILE-B-REC.
    PERFORM READ-NEXT-FILTER
       UNTIL FILE-B-FIELD IS NOT GREATER THAN FILE-A-FIELD.
    IF FILE-B-FIELD IS LESS THAN FILE-A-FIELD
      WRITE FILE-O-REC FROM FILE-B-REC.

READ-NEXT-FILTER.
    IF FILE-B-FIELD IS GREATER THAN FILE-A-FIELD
      READ FILE-A
        AT END MOVE HIGH-VALUES TO FILE-A-REC.

不需要任何标志，只需要文件状态。当然不需要创建依赖于布局的代码的邪恶执行。

这假设您的数据已按照您的指示进行排序。如果不是，那么方法会有所不同 - 将有问题的排除文件字段（两个字符）读入工作存储表，对表进行排序和搜索，以查找与读取的每个主文件记录的匹配项。

于 2015-05-19T05:53:08.987 回答