DOS Database Driver

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Database Drivers

Choosing the Right Database Driver

Common Database Driver Features

Driver Strings

 

DOS:Specifications

DOS:Data Types

DOS:Supported Commands and Attributes

DOS:Driver Strings

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