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BLOBIMPORT()
Read the contents of a file as a BLOB, identified by a memo field number
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Syntax
BLOBImport(<nFieldPos>, <cSourceFile>) --> lSuccess
Arguments
<nFieldPos> is the position of the field in the database file
structure.
<cSourceFile> is the name of the file from which to read the BLOB
data, including an optional drive, directory, and extension. See
SETDEFAULT() and SETPATH() for file searching and creation rules. No
default extension is assumed.
This function attempts to open <cSourceFile> in shared mode. If the
file does not exist, a runtime error is raised. If the file is
successfully opened, the operation proceeds. If access is denied
because another process has exclusive use of the file, for example,
NETERR() is set to true (.T.). Concurrency control:and BLOBIMPORT()
Note: There are no restrictions on the size of <cSourceFile> except
that you must have enough disk space to make the copy.
Returns
BLOBIMPORT() returns true (.T.) if successful; otherwise, it returns
false (.F.).
Description
BLOBIMPORT() provides a mechanism for copying the contents of a file
into a memo field as BLOB data. By default, this function operates on
the currently selected work area. It can be made to operate on an
unselected work area by specifying it within an aliased expression.
BLOBIMPORT() is used in conjunction with BLOBEXPORT() to transfer BLOB
data back and forth between files and memo fields. You can use
BLOBIMPORT() with a variety of file types, including graphic images,
word processor files, and printer fonts. These two functions are
excellent for creating databases for documents, graphics, sounds, etc.
Note: DBFieldInfo(DBS_BLOB_TYPE, <nFieldPos>) will return "C"
(string) for any memo field created using BLOBIMPORT().
Examples
. This example imports information from a word processing
document into a field, and then uses BLOBGET() to extract the first
25 characters of the field:
FUNCTION POPULATE()
USE customer NEW VIA "DBFCDX"
// Construct unique file name based on last
// name and id
DO WHILE .NOT. EOF()
GetPix("Pix", Substr(LastName, 1, 4) + CustID)
Customer->DBSKIP()
ENDDO
FUNCTION GetPix(cPixField, cPixFile)
LOCAL nPos
nPos := FieldPos(cPixField)
// Import the picture file into indicated field
IF !BLOBImport(nPos, cPixFile)
Alert("Import of picture " + cPixFile + ";
failed!")
ENDIF
See Also:
BLOBEXPORT()
DBFIELDINFO()
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