7.00 CREATEINDEX Example Gives "No Current Record" at Run-Time (62832)

MORE INFORMATION

The sample program found on Page 73 uses a file called BOOKS.MDB, the sample ISAM file that SETUP copies to your disk. However, in this program, the user-defined type, BookRec, does not match the record structure used in BOOKS.MDB. Also the program specifies a table name that does not exist in BOOKS.MDB.

The user-defined type, BookRec, should be defined as follows:

   TYPE BookRec
      IDNum AS DOUBLE
      Price AS CURRENCY
      Edition AS INTEGER
      Title AS STRING * 50
      Publisher AS STRING * 50
      Author AS STRING * 36
				

In addition, the table name should be defined as "BookStock" instead of "BooksStock".

The corrected program is as follows:

DEFINT A-Z
TYPE BookRec                   'altered user-defined type
   IDNum AS DOUBLE
   Price AS CURRENCY
   Edition AS INTEGER
   Title AS STRING * 50
   Publisher AS STRING * 50
   Author AS STRING * 36
END TYPE

DIM Library AS BookRec
DIM msgtxt AS STRING

CONST Database = "BOOKS.MDB"
CONST TableName = "BookStock" 'TableName = BookStock (not BooksStock)
TableNum = FREEFILE

OPEN Database FOR ISAM BookRec TableName AS TableNum
CREATEINDEX TableNum, "A", 0, "Author"
CREATEINDEX TableNum, "I", 1, "IDNum"
CREATEINDEX TableNum, "T", 0, "Title"
CREATEINDEX TableNum, "C", 0, "Price"
SETINDEX #1, "A"
CLS : LOCATE 13, 30
PRINT "choose a key:"
PRINT SPC(9); "move to:"; TAB(49); " order by: X "
PRINT : PRINT SPC(9); "F - first record"; TAB(49); "A - Author"
PRINT : PRINT SPC(9); "L - last record"; TAB(49); "I - ID number"
PRINT : PRINT SPC(9); "N - next record"; TAB(49); "T - Title"
PRINT : PRINT SPC(9); "P - previous record"; TAB(49); "C - Cost"
PRINT : PRINT SPC(9); "Q - Quit"; TAB(49); "X- no order"
LOCATE 3, 1: PRINT TAB(37); Books; ""
PRINT STRING$(80, "-");
VIEW PRINT 5 TO 10

MOVEFIRST TableNum
DO
    CLS
    RETRIEVE TableNum, Library
    PRINT "Author:   "; Library.Author;
    PRINT TAB(49); "ID #"; Library.IDNum
    PRINT "Title:      "; Library.Title
    PRINT "Publisher: "; Library.Publisher
    PRINT "cost:     "; Library.Price
    PRINT SPC(30); msgtxt
    PRINT STRING$(64, "-")
    IF GETINDEX$(TableNum) = "" THEN
         PRINT STRING$(15, "-");
    ELSE
         PRINT "index in use: "; GETINDEX$(TableNum);
    END IF

     validkeys$ = "FLNPQATICX"
     DO
         keychoice$ = UCASE$(INKEY$)
     LOOP WHILE INSTR(validkeys$, keychoice$) = 0 OR keychoice$ = ""
     msgtxt = ""

     SELECT CASE keychoice$
     CASE "F"
         MOVEFIRST TableNum
     CASE "L"
         MOVELAST TableNum
     CASE "N"
         MOVENEXT TableNum
         IF EOF(TableNum) THEN
             MOVELAST TableNum
             BEEP: msgtxt = "** at last record **"
         END IF
     CASE "P"
         MOVEPREVIOUS TableNum
         IF BOF(TableNum) THEN
             MOVEFIRST TableNum
             BEEP: msgtxt = "** at first record **"
         END IF
    CASE "Q"
         EXIT DO
    CASE ELSE
         VIEW PRINT
         LOCATE 13, 59: PRINT keychoice$;
         VIEW PRINT 5 TO 10
         IF keychoice$ = "X" THEN keychoice$ = ""
         SETINDEX TableNum, keychoice$
         MOVEFIRST TableNum
     END SELECT
LOOP

VIEW PRINT
DELETEINDEX TableNum, "A"
DELETEINDEX TableNum, "I"
DELETEINDEX TableNum, "T"
DELETEINDEX TableNum, "C"
CLOSE
END