What is DBF?
In This i Explain you about DBF and It's File Structure
Introduction
DBF is a file format typically used by database software. DBF stands for DataBase File. DBF files were originally used in dBase II and continued through to dBase Version IV.
DBF files can also be opened by Microsoft Excel and Microsoft Access.
DBF File Structure
| Byte offset |
Description |
| 0 |
DBF File type:
0x02 FoxBASE
0x03 FoxBASE+/Dbase III plus, no memo
0x30 Visual FoxPro
0x31 Visual FoxPro, autoincrement enabled
0x32 Visual FoxPro with field type Varchar or Varbinary
0x43 dBASE IV SQL table files, no memo
0x63 dBASE IV SQL system files, no memo
0x83 FoxBASE+/dBASE III PLUS, with memo
0x8B dBASE IV with memo
0xCB dBASE IV SQL table files, with memo
0xF5 FoxPro 2.x (or earlier) with memo
0xE5 HiPer-Six format with SMT memo file
0xFB FoxBASE |
| 1 - 3 |
Last update (YYMMDD) |
| 4 – 7 |
Number of records in file |
| 8 – 9 |
Position of first data record |
| 10 – 11 |
Length of one data record, including delete flag |
| 12 – 27 |
Reserved |
| 28 |
Table flags:
0x01 file has a structural .cdx
0x02 file has a Memo field
0x04 file is a database (.dbc)
This byte can contain the sum of any of the above values. For example, the value 0x03 indicates the table has a structural .cdx and a Memo field. |
| 29 |
Code page mark |
| 30 – 31 |
Reserved, contains 0x00 |
| 32 – n |
Field subrecords
The number of fields determines the number of field subrecords. One field subrecord exists for each field in the table. |
| n+1 |
Header record terminator (0x0D) |
| n+2 to n+264 |
Visual Foxpro only: A 263-byte range that contains the backlink, which is the relative path of an associated database (.dbc) file, information. If the first byte is 0x00, the file is not associated with a database. Therefore, database files always contain 0x00. |
Field Subrecords Structure
| Byte offset |
Description |
| 0 – 10 |
Field name with a maximum of 10 characters. If less than 10, it is padded with null characters (0x00). |
| 11 |
Field type:
C – Character
Y – Currency
N – Numeric
F – Float
D – Date
T – DateTime
B – Double
I – Integer
L – Logical
M – Memo
G – General
C – Character (binary)
M – Memo (binary)
P – Picture
+ – Autoincrement (dBase Level 7)
O – Double (dBase Level 7)
@ – Timestamp (dBase Level 7)
|
| 12 – 15 |
Displacement of field in record |
| 16 |
Length of field (in bytes) |
| 17 |
Number of decimal places |
| 18 |
Field flags:
0x01 System Column (not visible to user)
0x02 Column can store null values
0x04 Binary column (for CHAR and MEMO only)
0x06 (0x02+0x04) When a field is NULL and binary (Integer, Currency, and Character/Memo fields)
0x0C Column is autoincrementing |
| 19 - 22 |
Value of autoincrement Next value |
| 23 |
Value of autoincrement Step value |
| 24 – 31 |
Reserved |
|
File extension for DBF:
Primary association: Database
Mime type: application/dbase, application/x-dbase, application/dbf, application/x-dbf, zz-application/zz-winassoc-dbf.
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