Choosing the Right Database Driver
Common Database Driver Features
DOS:Supported Commands and Attributes
DOS:Specifications
The DOS file driver reads and writes any binary, byte-addressable files. Neither fields nor records are delimited. When reading a record, the driver reads the number of bytes defined in the file's RECORD structure, unless a length parameter is specified in the GET statement.
The DOS driver supports the length parameter for the ADD, APPEND, GET, and PUT statements; this allows for variable length records in a DOS file.
The POINTER function returns the relative byte position within the file of the beginning of the last record accessed by an ADD, APPEND, GET, or NEXT statement.
This file driver performs forward sequential processing only. No key or transaction processing functions are supported, and the PREVIOUS statement is not supported.
Due to its limitations, the main function of this driver is as a disk editor for binary files.
Files: | ClaDOSXL.LIB | Windows Static Link Library |
ClaDOSX.LIB | Windows Export Library | |
ClaDOSX.DLL | Windows Dynamic Link Library (32-bit) |
DOS:Data Types
BYTE | DECIMAL |
SHORT | PDECIMAL |
USHORT | STRING |
LONG | CSTRING |
ULONG | PSTRING |
SREAL | DATE |
REAL | TIME |
BFLOAT4 | GROUP |
BFLOAT8 |
DOS:File Specifications/Maximums
File Size: 4,294,967,295
Records per File: 4,294,967,295
Record Size: 64K
Field Size: 64K
Fields per Record: 64K
Keys/Indexes per File:n/a
Key Size: n/a
Memo fields per File: n/a
Memo Field Size: n/a
Open Data Files: Operating system dependent