COPY STRUCTURE EXTENDED
Copy current database structure into a definition file
COPY STRUCTURE EXTENDED TO <xcFileName>
<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.
COPY STRUCTURE EXTENDED create a new database named <cFileName> with a pre-defined structure (also called “structure extended file” ) :
Field name Type Length Decimals ----------- ---- ------ --------- FIELD_NAME C 10 0 FIELD_TYPE C 1 0 FIELD_LEN N 3 0 FIELD_DEC N 3 0
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.
// 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
COPY STRUCTURE, CREATE, CREATE FROM, DBCREATE(), DBSTRUCT(), __dbCopyStruct(), __dbCopyXStruct(), __dbCreate()