我正在尝试访问同一个文件来执行两项特定任务。第一项任务是更新，添加和删除记录。访问必须是随机的。第二个任务是在控制台上显示所有记录。访问必须是顺序的。我从COBOL收到code 65 File locked因为程序试图同时访问同一个文件两次。有没有办法解决这个错误？或者有不同的方法来做到这一点？或者我是否必须编写一个单独的程序来在控制台上显示记录？我被卡住了！
ENVIRONMENT DIVISION.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
SELECT MAST-FILE ASSIGN TO 'G:\CPSC315-COBOL\COBOLAssignments\P15-5\SALES.IND.TXT'
ORGANIZATION IS INDEXED
ACCESS IS RANDOM
RECORD KEY M-SALESPERSON-NUM.
SELECT MAST2-FILE ASSIGN TO 'G:\CPSC315-COBOL\COBOLAssignments\P15-5\SALES.IND.TXT'
ORGANIZATION IS INDEXED
ACCESS IS SEQUENTIAL
RECORD KEY M2-SALESPERSON-NUM.
DATA DIVISION.
FILE SECTION.
FD MAST-FILE
LABEL RECORDS ARE STANDARD.
01 MAST-RECORD.
05 M-SALESPERSON-NUM PIC XXX.
05 M-CUSTOMER-NAME PIC X(15).
05 M-TOTAL-SALES PIC 9(5)V99.
05 M-COST-OF-SALES PIC 9(4)V99.
FD MAST2-FILE
LABEL RECORDS ARE STANDARD.
01 MAST2-RECORD.
05 M2-SALESPERSON-NUM PIC X(3).
05 M2-SALESPERSON-NAME PIC X(15).
05 M2-TOTAL-SALES PIC 9(5)V99.
05 M2-COST-OF-SALES PIC 9(4)V99.
WORKING-STORAGE SECTION.
01 SALES-DATA.
05 SALESPERSON-NUM PIC X(3).
05 SALESPERSON-NAME PIC X(15).
05 TOTAL-SALES PIC 9(5)V99.
05 COST-OF-SALES PIC 9(4)V99.
01 OUTPUT-RECORD.
05 PIC X(1) VALUE SPACES.
05 O-SALESPERSON-NUM PIC X(3).
05 PIC X(3) VALUE SPACES.
05 O-SALESPERSON-NAME PIC X(3).
05 PIC X(3) VALUE SPACES.
05 O-TOTAL-SALES PIC 9(5)V99.
05 PIC X(3) VALUE SPACES.
05 O-COST-OF-SALES PIC 9(4)V99.
01 PROGRAM-DATA-ITEMS.
05 I-SALESPERSON-NUM PIC XXX.
05 WAIT-OK PIC X.
05 CHOICE PIC 9 VALUE 0.
05 READ-OK PIC X.
05 REWRITE-OK PIC X.
05 DELETE-OK PIC X.
PROCEDURE DIVISION.
10-MAINLINE.
OPEN I-O MAST-FILE
OPEN INPUT MAST2-FILE
PERFORM 20-PROCESS-LOOP
CLOSE MAST-FILE
MAST2-FILE
STOP RUN.
20-PROCESS-LOOP.
PERFORM UNTIL CHOICE = 5
PERFORM 30-DISPLAY-MENU
EVALUATE CHOICE
WHEN 1
PERFORM 40-UPD-SALES
WHEN 2
PERFORM 90-ADD-SALES
WHEN 3
PERFORM 110-DELETE-SALES
WHEN 4
PERFORM 120-DISPLAY-SALES
END-EVALUATE
END-PERFORM.
30-DISPLAY-MENU.
DISPLAY 'SALES MAINTENANCE SYSTEM'
DISPLAY ' '
DISPLAY ' SELECT ONE:'
DISPLAY ' '
DISPLAY ' 1. UPDATE SALES RECORD'
DISPLAY ' 2. ADD SALES RECORD'
DISPLAY ' 3. DELETE SALES RECORD'
DISPLAY ' 4. DISPLAY SALES RECORD'
DISPLAY ' 5. QUIT'
DISPLAY ' '
DISPLAY 'ENTER CHOICE (1 - 5): ' WITH NO ADVANCING
ACCEPT CHOICE
PERFORM UNTIL CHOICE >= 1 AND <= 5
DISPLAY ' '
DISPLAY 'ERROR: ENTER CHOICE (1 - 5): ' WITH NO ADVANCING
ACCEPT CHOICE
END-PERFORM.
40-UPD-SALES.
DISPLAY 'UPDATE SALES: ENTER SALESPERSON NUMBER: ' WITH NO ADVANCING
ACCEPT SALESPERSON-NUM
MOVE SALESPERSON-NUM TO M-SALESPERSON-NUM
PERFORM 50-READ-RECORD
IF READ-OK = 'N'
DISPLAY 'RECORD DOES NOT EXIST - PRESS ENTER'
ACCEPT WAIT-OK
ELSE
DISPLAY SALES-DATA
PERFORM 100-INPUT-NEW-RECORD
PERFORM 60-REWRITE-RECORD
END-IF.
50-READ-RECORD.
MOVE 'Y' TO READ-OK
READ MAST-FILE INTO SALES-DATA
INVALID KEY
MOVE 'N' TO READ-OK
END-READ.
60-REWRITE-RECORD.
REWRITE MAST-RECORD FROM SALES-DATA
INVALID KEY
DISPLAY 'REWRITE ERROR: SALESPERSON NUMBER ' SALESPERSON-NUM
DISPLAY 'PRESS ENTER TO CONTINUE'
ACCEPT WAIT-OK
END-REWRITE.
70-WRITE-RECORD.
MOVE 'Y' TO REWRITE-OK
WRITE MAST-RECORD FROM SALES-DATA
INVALID KEY
MOVE 'N' TO REWRITE-OK
END-WRITE
IF REWRITE-OK = 'N'
DISPLAY 'WRITE ERROR: SALESPERSON NUMBER ' SALESPERSON-NUM
DISPLAY 'PRESS ENTER TO CONTINUE'
ACCEPT WAIT-OK
END-IF.
80-DELETE-RECORD.
MOVE 'Y' TO DELETE-OK
DELETE MAST-FILE
INVALID KEY
MOVE 'N' TO DELETE-OK
END-DELETE
IF REWRITE-OK = 'N'
DISPLAY 'WRITE ERROR: SALESPERSON NUMBER ' SALESPERSON-NUM
DISPLAY 'PRESS ENTER TO CONTINUE'
ACCEPT WAIT-OK
END-IF.
90-ADD-SALES.
DISPLAY 'ADD SALES RECORD: ENTER SALESPERSON NUMBER: ' WITH NO ADVANCING
ACCEPT SALESPERSON-NUM
MOVE SALESPERSON-NUM TO M-SALESPERSON-NUM
PERFORM 50-READ-RECORD
IF READ-OK = 'Y'
DISPLAY 'RECORD ALREADY EXISTS - PRESS ENTER'
ACCEPT WAIT-OK
ELSE
PERFORM 100-INPUT-NEW-RECORD
PERFORM 70-WRITE-RECORD
IF REWRITE-OK = 'Y'
DISPLAY 'RECORD ' SALESPERSON-NUM ' ADDED TO FILE'
DISPLAY 'PRESS ENTER TO CONTINUE'
ACCEPT WAIT-OK
END-IF
END-IF.
100-INPUT-NEW-RECORD.
MOVE SALESPERSON-NUM TO M-SALESPERSON-NUM
DISPLAY ' ENTER SALESPERSON NAME: ' WITH NO ADVANCING
ACCEPT SALESPERSON-NAME
DISPLAY ' ENTER TOTAL SALES: ' WITH NO ADVANCING
ACCEPT TOTAL-SALES
DISPLAY ' ENTER COST OF SALES: ' WITH NO ADVANCING
ACCEPT COST-OF-SALES.
110-DELETE-SALES.
DISPLAY 'DELETE SALES RECORD: ENTER SALESPERSON NUMBER: ' WITH NO ADVANCING
ACCEPT SALESPERSON-NUM
MOVE SALESPERSON-NUM TO M-SALESPERSON-NUM
PERFORM 50-READ-RECORD
IF READ-OK = 'N'
DISPLAY 'RECORD DOES NOT EXIST - PRESS ENTER'
ACCEPT WAIT-OK
ELSE
PERFORM 80-DELETE-RECORD
IF DELETE-OK = 'Y'
DISPLAY 'RECORD DELETED - PRESS ENTER'
ACCEPT WAIT-OK
END-IF
END-IF.
120-DISPLAY-SALES.
MOVE SALESPERSON-NUM TO M2-SALESPERSON-NUM
MOVE SALESPERSON-NAME TO M2-SALESPERSON-NAME
MOVE TOTAL-SALES TO M2-TOTAL-SALES
MOVE COST-OF-SALES TO M2-COST-OF-SALES
READ MAST2-FILE
AT END MOVE HIGH-VALUES TO M2-SALESPERSON-NUM
END-READ
PERFORM UNTIL M2-SALESPERSON-NUM = HIGH-VALUES
MOVE M2-SALESPERSON-NUM TO O-SALESPERSON-NUM
MOVE M2-SALESPERSON-NAME TO O-SALESPERSON-NAME
MOVE M2-TOTAL-SALES TO O-TOTAL-SALES
MOVE M2-COST-OF-SALES TO O-COST-OF-SALES
DISPLAY OUTPUT-RECORD
READ MAST2-FILE
AT END MOVE HIGH-VALUES TO M2-SALESPERSON-NUM
END-READ
END-PERFORM.
end program Program1.
答案 0 :(得分：2)
当您打开文件I-O时，这意味着您为输入和输出打开它。摆脱你的第二个档案。
要定位文件以显示数据，您可以使用KEY读取，然后阅读READ ... NEXT ...，或者您可以使用START ...然后READ ... NEXT。
始终在ASSIGN中使用文件状态。然后使用文件状态字段告诉COBOL将文件状态置于，以检查以前的IO。将其用于文件结尾（值“10”）。使用88s。然后，您不需要INVALID KEY和AT END，并且与IO关联的所有END语句都可以，因为您没有IO的内置条件。这将简化事情。
你的结构非常适合初学者。刷新看不到PERFORM ...... THRU ....
我建议您尝试在第12列中单个完整停止/期间的效果。然后，您就可以从段落中移动最后一行代码，而不必考虑附加到它的句点/句点（因为它没有附加到它上面）。
使用更多PERFORMs。 OPEN和CLOSE对程序的逻辑并不重要。将它们隐藏在段落中，对它们进行文件状态检查。与READ / WRITE / DELETE以及您最终使用的任何其他IO语句相同。将它们隐藏在您要执行的命名良好的程序中。
考虑一些IF的大小（行数）。将代码放在一个命名良好的过程中，代码可以由人类高级“读取”，只有在需要时才会查看详细信息。
不要，不要，不要，乱用两个文件。不要，不要，不要两次打开同一个文件（我在我的时间里写过一些COBOL程序，而且我从来没有，认为这是一种合理的方式来实现任何目标，更不用说你拥有的简单任务了）。
你可能想要考虑DYNAMIC而不是RANDOM（这就是它的用途）。如果您仅进行随机访问，则使用RANDOM。您实际上也想要进行顺序访问（查找跳过顺序访问的参考以供进一步讨论）。
SELECT MAST-FILE ASSIGN TO 'G:\CPSC315-COBOL\COBOLAssignments\P15-5\SALES.IND.TXT'
ORGANIZATION IS INDEXED
ACCESS IS RANDOMREWRITE-OK = 'N'
RECORD KEY M-SALESPERSON-NUM
FILE STATUS IS W-MAST-FILE-STATUS.
...
01 W-MAST-FILE-STATUS PIC XX.
88 W-MAST-FILE-LAST-IO-OK VALUE "00".
88 W-MAST-FILE-EOF VALUE "10".
88 W-MAST-FILE-REC-NOT-FOUND VALUE "23".
88 W-MAST-FILE-OR-OR-NOT-FOUND VALUE "00" "23".
...
50-READ-RECORD.
MOVE 'Y' TO READ-OK
READ MAST-FILE INTO SALES-DATA
INVALID KEY
MOVE 'N' TO READ-OK
END-READ.
变为：
50-READ-RECORD.
READ MAST-FILE KEY key-name INTO SALES-DATA
IF NOT ( W-MAST-FILE-OR-OR-NOT-FOUND )
some code to deal with the pickle, which is nothing to do with
business-logic, so hide it away
END-IF
.
80-DELETE-RECORD.
MOVE 'Y' TO DELETE-OK
DELETE MAST-FILE
INVALID KEY
MOVE 'N' TO DELETE-OK
END-DELETE
IF REWRITE-OK = 'N'
DISPLAY 'WRITE ERROR: SALESPERSON NUMBER ' SALESPERSON-NUM
DISPLAY 'PRESS ENTER TO CONTINUE'
ACCEPT WAIT-OK
END-IF.
变为：
80-DELETE-RECORD.
DELETE MAST-FILE
IF NOT W-MAST-FILE-LAST-IO-OK
DISPLAY 'WRITE ERROR: SALESPERSON NUMBER ' SALESPERSON-NUM
DISPLAY 'PRESS ENTER TO CONTINUE'
ACCEPT WAIT-OK
END-IF
.
每个IO段都变得自包含，自我验证，并且当您处于业务逻辑中时，FILE STATUS字段自然只具有良好的条件。你可以在这些段落中处理“不可能发生”（但有一天）。
您在其他地方的代码简化了。您的“标志”数量减少了（FILE STATUS字段的值取代了标志的需要）您的IO没有条件部分，所以不需要END范围分隔符。
关于编号段落的提示。在经过充分测试以致您对逻辑结构感到满意之前，请不要这样做。一旦你对此感到满意，重新排列段落，以便段落在之后 。然后把数字打开。然后代码的物理布局代表程序逻辑的结构。
如果你是第一个，你最终会得到你所拥有的情况 - 你有数字，但他们没有推断。 “重新编号”段落比在没有段落编号的情况下添加段落编号要繁琐得多（使用编辑器/实用程序的强大功能来进行编号）。