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COPY STRUCTURE EXTENDED
Copy field definitions to a .dbf file
------------------------------------------------------------------------------
Syntax
COPY STRUCTURE EXTENDED
TO <xcExtendedDatabase>
Arguments
TO <xcExtendedDatabase> is the name of the target structure extended
database file. This argument can be specified either as a literal
database file name or as a character expression enclosed in parentheses.
Description
COPY STRUCTURE EXTENDED creates a database file whose contents is the
structure of the current database file with a record for the definition
of each field. The structure extended database file has the following
structure:
Structure of an Extended File
------------------------------------------------------------------------
Field Name Type Length Decimals
------------------------------------------------------------------------
1 Field_name Character 10
2 Field_type Character 1
3 Field_len Numeric 3 0
4 Field_dec Numeric 4 0
------------------------------------------------------------------------
Used in application programs, COPY STRUCTURE EXTENDED permits you to
create or modify the structure of a database file programmatically. To
create a new database file from the structure extended file, use CREATE
FROM. If you need an empty structure extended file, use CREATE.
Notes
. Character field lengths greater than 255: In CA-Clipper, the
maximum character field length is 64K. For compatibility reasons,
field lengths greater than 255 are represented as a combination of
the Field_dec and Field_len fields. After COPYing STRUCTURE
EXTENDED, you can use the following formula to determine the length
of any character field:
nFieldLen := IF(Field_type = "C" .AND. ;
Field_dec != 0, Field_dec * 256 + ;
Field_len, Field_len)
Examples
. This example creates Struc.dbf from Sales.dbf as a structure
extended file and then lists the contents of Struc.dbf to illustrate
the typical layout of field definitions:
USE Sales NEW
COPY STRUCTURE EXTENDED TO Struc
USE Struc NEW
LIST Field_name, Field_type, Field_len, Field_dec
Result:
1 BRANCH C 3 0
2 SALESMAN C 4 0
3 CUSTOMER C 4 0
4 PRODUCT C 25 0
5 AMOUNT N 8 2
6 NOTES C 0 125
// Field length is 32,000 characters
Files Library is CLIPPER.LIB.
See Also:
COPY STRUCTURE
CREATE
CREATE FROM
FIELDNAME()
TYPE()
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