With any type of database or connection, you can: You can't create additional DBEngine objects, and the DBEngine object isn't an element of any collection. The DBEngine object contains and controls all other objects in the hierarchy of DAO objects. SaveToFile process is what strips it out.The DBEngine object is the top level object in the DAO object model. Value of the Field2 object you will still get the metadata at the beginning of the byte sequence the. While ((!"Document1.pdf".Equals()) & (!rstAttach.EOF))įield2 fld = that if you try to use the. "SELECT Attachments FROM AttachTest WHERE ID=1", ĭatabase db = rstMain = db.OpenRecordset( SaveToFile method of an ACE DAO Field2 object, like so: // required COM reference: Microsoft Office 14.0 Access Database Engine Object Library The only Official™ way of extracting files from an Attachment field in Access is to use the. Unfortunately not all file formats and applications are so forgiving of extraneous bytes at the beginning of the file. Then the resulting file will include the metadata at the beginning of the file (20 bytes in this case)Īdobe Reader is able to open this file because it is robust enough to ignore any "junk" that may appear in the file before the '%PDF-1.4' signature. Using (OleDbDataReader rdr = cmd.ExecuteReader()) "WHERE Attachments.FileName='Document1.pdf'" If we use the following code to try and extract the PDF file to disk using (OleDbCommand cmd = new OleDbCommand()) The beginning of that PDF file looks like this:
To illustrate, a document named "Document1.pdf" is saved to an Attachment field using the Access UI. The Access Database Engine prepends some metadata to the binary contents of the file, and that metadata is included if we retrieve the.
Unfortunately we cannot directly retrieve the contents of a file in an Access Attachment field using OleDb. It worked okay for PDF files that were subsequently opened with Adobe Reader, but it did not always work properly for other types of files. (My original answer to this question was misleading.
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