COPY STRUCTURE EXTEND

Copy current database structure into a definition file

Syntax

COPY STRUCTURE EXTENDED TO <xcFileName>

Arguments

TO <xcFileName> The name of the target definition file to create. (.dbf) is the default extension if none is given. It can be specified as a literal file name or as a character expression enclosed in parentheses.

Description

COPY STRUCTURE EXTENDED create a new database named with a pre-defined structure (also called "structure extended file"):

Field nameTypeLengthDecimals
FIELD_NAMEC100
FIELD_TYPEC10
FIELD_LENN30
FIELD_DECN30


Each record in the new file contains information about one field in the original file. CREATE FROM could be used to create a database from the structure extended file.

For prehistoric compatibility reasons, Character fields which are longer than 255 characters are treated in a special way by writing part of the length in the FIELD_DEC according to the following formula (this is done internally):


FIELD->FIELD_DEC := int( nLength / 256 )
FIELD->FIELD_LEN := ( nLength % 256 )


Later if you want to calculate the length of a field you can use the following formula:


nLength := IIF( FIELD->FIELD_TYPE == "C", ;
FIELD->FIELD_DEC * 256 + FIELD->FIELD_LEN, ;
FIELD->FIELD_LEN )


COPY STRUCTURE EXTENDED command is preprocessed into __dbCopyXStruct() function during compile time.

Examples

// Open a database, then copy its structure to a new file,
// Open the new file and list all its records
USE Test
COPY STRUCTURE EXTENDED TO TestStru
USE TestStru
LIST

Status

Ready

Compliance

COPY STRUCTURE EXTENDED works exactly as in CA-Clipper

Platforms

All

See Also