Category : Pascal Source Code
Archive   : DBBROW20.ZIP
Filename : DBASEBRO.DOC

Dbase III DBF File Structure


Header
------



BYTE # Type Example Description
------ ---- ------- -----------

0 Byte 1 DBASE Version
(83H with DBT file)
(03H without DBT file)

1 Byte 2 Year - Binary

2 Byte 3 Month - Binary

3 Byte 4 Day - Binary

4-7 32 bit integer 5 Number of records in file

8-9 16 bit integer 6 Length of header

10-11 16 bit integer 7 Length of record

12-31 20 Bytes 8 Reserved

32-n 32 Bytes Field Descriptor
(See below)

n+1 Byte 9 0Dh field terminator

N+2 Byte 10 00h In some older versions
(The length of header byte
reflects this if present)
.pa

Field Descriptor
----------------

BYTE # Type Example Description
------ ---- ------- -----------

0-10 byte 11 Field name
(Zero filled)

11 Byte 12 Field Type
(N D L C M)

12-15 32 bit integer 13 Field data address
(Internal use)

16 Byte 14 Field length - Binary

17 Byte 15 Field decimal count - Binary

18-31 14 bytes 16 Reserved



Field Types
-----------


N Numeric - 0 1 2 3 4 5 6 7 8 . -


D Date - 8 Bytes (YYYYMMDD)


L Logical - Y y N n T t F f ? (? = Not initialized)


C Character - Any Ascii Character


M Memo - 10 digits (DBT block Number)



Data Records
------------


All data is in Ascii.


There is no field seperators or record terminators.

The first byte is a space (20h) if record not deleted and an
asterick (2AH) if deleted.



DBASE Limitations
-----------------

Fields - 128 Max.

Record - 4000 bytes Max.

Header - 4130 bytes Max.

(128 Fields * 32 bytes) + 32 bytes + 1 terminator + (1 null)

Number - 19 digits




Example File
------------


1 2 3 4 5 6 7 8
|| || || || |---------| |---| |---| |----------
000000 83 55 0B 0E 31 00 00 00-81 01 89 00 00 00 00 00 .U..1...........

----------------------------------------------|
000010 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................

11 12 13
|------------------------------| || |---------|
000020 46 49 52 53 54 4E 41 4D-45 00 00 43 13 01 9D 41 FIRSTNAME..C...A

14 15 16
|| || |---------------------------------------|
000030 14 00 00 00 01 00 00 00-00 00 00 00 00 00 00 00 ................

000040 4C 41 53 54 4E 41 4D 45-00 00 00 43 27 01 9D 41 LASTNAME...C'..A

000050 14 00 00 00 01 00 00 00-00 00 00 00 00 00 00 00 ................

000060 50 48 4F 4E 45 00 00 00-00 00 00 43 3B 01 9D 41 PHONE......C;..A

000070 0D 00 00 00 01 00 00 00-00 00 00 00 00 00 00 00 ................

000080 54 52 41 56 45 4C 43 4F-44 45 00 43 48 01 9D 41 TRAVELCODE.CH..A

000090 04 00 00 00 01 00 00 00-00 00 00 00 00 00 00 00 ................

0000A0 54 52 41 56 45 4C 50 4C-41 4E 00 43 4C 01 9D 41 TRAVELPLAN.CL..A

0000B0 28 00 00 00 01 00 00 00-00 00 00 00 00 00 00 00 (...............

0000C0 44 45 50 41 52 54 55 52-45 00 00 44 74 01 9D 41 DEPARTURE..Dt..A

0000D0 08 00 00 00 01 00 00 00-00 00 00 00 00 00 00 00 ................

0000E0 43 4F 53 54 00 50 41 49-44 00 00 4E 7C 01 9D 41 COST.PAID..N|..A

0000F0 0A 02 00 00 01 00 00 00-00 00 00 00 00 00 00 00 ................

000100 50 41 49 44 00 4F 54 45-53 00 00 4C 86 01 9D 41 PAID.OTES..L...A

000110 01 00 00 00 01 00 00 00-00 00 00 00 00 00 00 00 ................

000120 41 47 45 4E 54 00 00 00-00 00 00 43 87 01 9D 41 AGENT......C...A

000130 02 00 00 00 01 00 00 00-00 00 00 00 00 00 00 00 ................

000140 52 45 53 45 52 56 44 41-54 45 00 44 89 01 9D 41 RESERVDATE.D...A

000150 08 00 00 00 01 00 00 00-00 00 00 00 00 00 00 00 ................

000160 4E 4F 54 45 53 00 00 00-00 00 00 4D 91 01 9D 41 NOTES......M...A

000170 0A 00 00 00 01 00 00 00-00 00 00 00 00 00 00 00 ................

Firstname
|| |----------------------------------------
000180 0D 20 43 6C 61 69 72 65-20 20 20 20 20 20 20 20 . Claire

Lastname
----------------| |----------------------------
000190 20 20 20 20 20 20 42 75-63 6B 6D 61 6E 20 20 20 Buckman

Phone
----------------------------| |----------------
0001A0 20 20 20 20 20 20 20 20-20 20 28 35 35 35 29 34 (555)4

T - code T - plan
-------------------| |---------| |-------------
0001B0 35 36 2D 39 30 35 39 43-49 31 30 31 30 2D 6E 69 56-9059CI1010-ni

-----------------------------------------------
0001C0 67 68 74 20 43 61 72 69-62 62 65 61 6E 20 49 73 ght Caribbean Is

-----------------------------------------------
0001D0 6C 61 6E 64 20 43 72 75-69 73 65 20 20 20 20 20 land Cruise

Departure Date Cost
-------| |---------------------| |-------------
0001E0 20 20 20 31 39 38 35 31-30 32 34 20 20 20 31 31 19851024 11

PD Age Res. Date
-------------| || |---| |---------------------|
0001F0 39 39 2E 30 30 54 4D 4D-31 39 38 35 30 37 31 35 99.00TMM19850715

.pa
Notes
|---------------------------|
000200 20 20 20 20 20 20 20 20-20 31 20 52 69 63 6B 20 1 Rick

000210 20 20 20 20 20 20 20 20-20 20 20 20 20 20 20 4C L

000220 69 73 62 6F 6E 6E 20 20-20 20 20 20 20 20 20 20 isbonn

000230 20 20 20 28 35 35 35 29-34 35 35 2D 33 33 34 34 (555)455-3344

000240 41 56 31 30 39 2D 6E 69-67 68 74 20 41 6C 61 73 AV109-night Alas

000250 6B 61 2F 56 61 6E 63 6F-75 76 65 72 20 43 72 75 ka/Vancouver Cru

000260 69 73 65 20 20 20 20 20-20 20 20 20 31 39 38 35 ise 1985

000270 30 38 30 35 20 20 20 31-33 37 38 2E 30 30 54 4A 0805 1378.00TJ

000280 54 31 39 38 35 30 37 31-35 20 20 20 20 20 20 20 T19850715

000290 20 20 32 20 48 61 6E 6B-20 20 20 20 20 20 20 20 2 Hank