Downloading from a Database

With FileUpEE, you can download a file from a directory or a database. To download a file, use the FileUpEE method TransferFile, or - as in the following example - the FileEE method WriteToResponse.

The example downloads a file from the database upload.mdb on the file server. The file is downloaded to the Web server and then to the client. You will find upload.mdb in FileUpEE\doc-samples\samples. Note that the asp scripts in this example use the include file include.inc.asp.

The database download example includes three scripts:

• Form.asp
  The upload form.



• Download.asp
  The Web server script. Webserver.asp includes all server-side download processing instructions.



• FileServer.asp
  The file server script. FileServer.asp executes the instructions that were set in Download.asp.

Form.asp

Form.asp displays a table of all files in the database upload.mdb, and a Download link for each file. A SQL query is used to get the information about the files in the database. The query gets the values of the UploadTable columns ID, FileName, ByteSize, ContentType, and Comment:

	Set oConn = Server.CreateObject("ADODB.Connection")

	'--- Application("connString") is a variable defined in 
	'--- doc-samples\global.asa.  It is the path 
	'--- FileUpEE\doc-samples\samples\upload.mdb.
	oConn.Open Application("connString")

	'--- The RecordSet object oRS contains ID, FileName,
	'--- ByteSize, ContentType, and Comment - all the UploadTable 
	'--- fields except for the actual file.
	Set oRS = oConn.Execute("SELECT ID, FileName, ByteSize, ContentType, Comment FROM UploadTable")

	'--- If there are no files in the database, this  
	'--- message will be displayed.    
	'--- Before you run the database upload sample, 
	'--- upload.mdb should contain one file.  Each time you run 
	'--- the database upload sample, you will add a file to 
	'--- upload.mdb.
	If oRS.EOF And oRS.BOF Then
		Response.Write("There are no files currently in the database.")
		Response.End
	End If

An HTML table displays the information about the files and a Download link for each file. Clicking Download sends a request to Download.asp with two values in the query string - the file name, and the file id:

	Response.Write("<TD>[<A HREF=""webserver.asp?name=" &_
		oRS.Fields("FileName").Value & "&id=" & oRS.Fields("ID").Value &_ 
		""">Download</A>]</TD>")

Download.asp

The database upload.mdb is on the file server. The requested file will be downloaded from the file server to the Web server and then to the client. Download.asp is on the Web server and contains all download instructions. These will be executed automatically in FileServer.asp.

	strFileName = Request.QueryString("name")
	...
	Set oDownFile = oFileUpEE.AddDbDownloadFile(strFileName)

The file name you pass to AddDbDownloadFile does not have to be the file name in the database, as it is in this sample. The file name passed to AddDbDownloadFile is the name that will be displayed to the user when the file is downloaded.

You can set the database connection string for the upload - using FileUpEE.DbConnection - or for the file - using FileEEDbConnection. In Download.asp, the connection string is set by the FileEE object's DbConnection property:

	'--- Application("connString") is a variable defined in 
	'--- doc-samples\global.asa.  It is the path 
	'--- FileUpEE\doc-samples\samples\upload.mdb.
	oDownFile.DbConnection = Application("connString")

When downloading a file from a database, to tell FileUpEE where to find the file, you must set the file's table name, primary key column, primary key value, and file column name:

	oDownFile.DbTableName = "UploadTable"
	oDownFile.DbPrimaryKey = "ID"
	oDownFile.DbPrimaryKeyValue = intFileID
	oDownFile.DbFileColumnName = "FileBinary"

After calling AddDbDownloadFile and providing the necessary information about the file to download, the download request is sent to the file server:

	intSAResult = oFileUpEE.SendRequest()

If the Processed property returns saDownloaded, the file was successfully downloaded from the file server to the Web server. The WriteToResponse method then takes the response from the file server and downloads the file to the client:

	'--- If the file was retrieved from the fileserver successfully
	'--- stream it down to the client
	If oDownFile.Processed = saDownloaded Then
		Response.ContentType = "application/unknown"
		oDownFile.WriteToResponse Response
	Else

FileServer.asp

	objFileUpEE.ProcessRequest Request, True, True

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See Also

The example uses the method WriteToResponse to download a file. Alternatively, use the method TransferFile.

Per-upload database properties: FileUpEE.DbConnection, FileUpEE.DbPrimaryKey, FileUpEE.DbPrimaryKeyValue, FileUpEE.DbSqlCommand, FileUpEE.DbTableName and FileUpEE.SaveMethod.

Per-file database properties: FileEE.DbConnection, FileEE.DbFileColumnName, FileEE.DbIdentityColumnName, FileEE.DbPrimaryKey, FileEE.DbPrimaryKeyValue, FileEE.DbSqlCommand, FileEE.DbTableName, and FileEE.DbSchema.

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