Tag Archives: SQL Blob Export

Using date and time values in your file naming convention

In SQL Image Viewer, Access OLE Export, and SQL Blob Export, you can use date values in the file naming convention.

In this query, we select the ID (integer), content (blob), and lastupdated (datetime) fields.

To use the date value from the lastupdated field, include it in the file naming convention value.

The file name then uses the default format of yyyymmdd to format the date value.

You can also format the date value differently using date and time specifiers.  For e.g. using <LASTUPDATE:yyyy_mm> indicates that we only want to use the year and month elements separated by an underscore character.

resulting in

You can also use the time values e.g. hhnn indicates we want to use the hour and minute values:

resulting in this:

You can use both and and time values by using the appropriate specifiers.  The thing to note is that minute specifiers use n or nn, instead of m or mm, as those are month specifiers.

A list of all date and time specifiers available here for reference.

 

Extracting files from a Thomson Reuters FileCabinet CS database

We recently had a user that had to extract Word and Excel documents from a Thomson Reuters FileCabinet CS database using  SQL Blob Export.  The user was helpful enough to send us a couple of samples of the raw data stored in the table, allowing us to inspect the data in detail.

Turns out Thomson Reuters stores the files in a different manner to what SQL Blob Export expected, so we had to make some adjustments to the export process.

Beginning with version SQL Blob Export 6.1, you can now export items from your FileCabinet CS database.  The same feature is found in SQL Image Viewer.  When you run a query to return the items, it will be shown as OLE Structured Storage packages.

You can then export the files using the export wizards.

If you encounter a situation where SQL Blob Export or SQL Image Viewer is unable to export your files, please send us an email at support@yohz.com.

It would be very helpful to also attach a couple of samples of the rows that failed to be exported.  To extract the data exactly as stored in the database in SQL Blob Export, please do the following:

  • select the Extract bin files option on the Options page
  • once the export process has completed, you will find files with the .bin extension.  Please send us a couple of those files so that we may check how the data is stored in your database.

 

High DPI support

We recently added high DPI support to some of our applications so that they render better when user displays are scaled to 125% or more.  We may have missed 1 or 2 items, so if you encounter any GUI elements that are oversized or undersized, we would appreciate it very much if you could let us know at support@yohz.com.

The applications we’ve added high DPI support for are:

Extracting and viewing PDF files in a SimpleIndex database

SimpleIndex is an application that stores PDF files in SQL Server databases.  The PDFs are stored in the General table, in the Image column.  That column is of the SQL Server image type, generally used to store binary data (or blobs).

We recently had a user that could not export the PDF files from his SimpleIndex database.    The user was very helpful to send us the original PDF file, and the PDF file content as stored in his database for comparison.  Turns out that SimpleIndex first converts the binary data in your PDF files to a unicode text string, then stores this unicode text.

This is certainly a strange way to go about storing a file in a column that has a data type that’s perfectly suited to storing binary files.  In addition to making it difficult to extract the PDF file, it doubles the storage requirements.  Whatever the reason, SQL Image Viewer could not identify and display the PDF files.

So the first thing we did was to convert the exported ‘mangled’ PDF files back to their original state.  We added this feature to our UTF8Tool application.

Now the user could export the content from his database, then use this tool to convert those files into proper PDF files.

However, the user wanted to be able to query and view the PDF files from within SQL Image Viewer.  We ended up with the easiest option – we created a second column to store the proper PDF content, then create an application to convert the mangled PDF files from the first column and store them in this new column.

It’s a very basic unpolished conversion application, and you can download and use this application freely.

IMPORTANT NOTE:  This application updates a column in your database, so please make a backup of your database first, in case things don’t turn out exactly the way you want it.

Currently, this application supports only SQL Server databases.  If you need a version that supports another database engine, or if you require some modifications, drop us a line at support@yohz.com.

Now that the user could display the PDF directly in SQL Image Viewer, we had another issue.  By default, SQL Image Viewer only displays the first page of each PDF file that it detects e.g.

This made it difficult to review each PDF file in details.  Fortunately, SQL Image Viewer (professional edition) supports custom layouts.  With custom layouts, you can choose to display a specific number of pages from your PDF files, and also the size of the pages e.g.

Now the user could easily preview more of his PDF files prior to exporting them.

In summary:

  • if you need to convert binary data from unicode files to ansi files, give our free UTF8Tool a try
  • if you want to convert a column containing binary data in unicode text format to ansi text format and store the converted data in a separate column, give this free application a try (but please back up your database first)
  • if you want to preview multiple pages of a PDF file, use the custom layouts feature in SQL Image Viewer (professional edition)
  • if you have data that SQL Image Viewer/Access OLE Export/SQL Blob Export does not recognize, send us an email at support@yohz.com

 

Extracting files from a ProgressCRM database

We recently had a user who needed to extract files from a SQL Server database created by ProgressCRM and needed help.  He was helpful enough to send us a couple of the sample files that were not extracted correctly.

It turned out that each file that was being uploaded was stored in an OLE container.  Normally, our products (SQL Image Viewer, Access OLE Export, and SQL Blob Export) can extract the embedded files, but in this case, the entire OLE container itself had a 12-byte prefix, most likely added by ProgressCRM for their internal use.

So the task was to first extract the content without the 12-byte prefix, and then let SQL Blob Export handle the extraction of the files from the OLE container.

Luckily, this was easy enough to do in a SQLServer database.  We could use the SUBSTRING command to retrieve only the content from the 13-th byte onwards e.g.

SELECT SUBSTRING(CAST(<the column containing the binary data> AS VARBINARY(MAX)), 13, DATALENGTH(content))  FROM <the table name>

So if you find that your application is uploading your files with their own prefix data, you can use the SUBSTRING function (in SQL Server) to remove the prefix so that our products can recognize the actual file content and export them for you correctly.

Improved debugging in Access OLE Export / SQL Blob Export

Sometimes it happens that you may have some items that Access OLE Export or SQL Blob Export is unable to export correctly.  This can be due to many reasons e.g.

  • the binary data has been compressed by the uploading application
  • the binary data has been encrypted by the uploading application
  • the uploading application has appended additional header bytes to the data
  • an unsupported OLE server was used to upload the file

To troubleshoot these issues, we would ask the user to send us the raw data exactly as stored in the database.  This usually involves using SQL Image Viewer to perform the extraction.

We’ve now added the option to extract the raw data using Access OLE Export / SQL Blob Export.  You can do this by selecting the debugging – create bin files for analysis item.

Now when you have problems exporting your files, selecting this option will cause a raw copy of the data to be exported together, with the .debug.bin extension.  You can then send us these .debug.bin files for further analysis.

Extracting binary data from a nvarchar(max) column

Recently we had a user that needed to extract PDF files stored in a SQL Server nvarchar(max) column.  Now, you wouldn’t normally be able to store binary files correctly in a text column, but the application they used (Deacom) first encoded the PDF file to UTF-8 text, then stored the UTF-8 text into the text column.

While SQL Image Viewer (and SQL Blob Export/Access OLE Export) could extract the UTF-8 encoded data from the table and store it in a file, the resulting PDF file cannot be opened because the data contained therein is invalid.  So we had to provide a small utility to convert the UTF-8 encoded file back to its original contents.  You can read more about the utility here.

After converting the PDF files, the user then compressed the PDF files and now wanted to upload the PDF files back into the database.  They used SQL File Import to perform the upload, but first the PDF files had be to UTF-8 encoded again, otherwise the application (Deacom) could not open the PDF files.  That can also be one using the above utility.

Finally, we had one last issue where only 8 Kb of the encoded PDF file was being uploaded.  The cause was traced to the use of the MDAC/ODBC driver to connect to SQL Server.

In our database products, when you connect to a SQL Server instance, the default is to let the application select the best available drivers.

By design, our products will use the SQL Server Native Client drivers if available, and only use MDAC/ODBC drivers when the Native Client drivers are not available.  However, MDAC/ODBC drivers limit text fields to only 8000 bytes.

When the user attempted to use the Native Client driver, the connection failed.

Installing and using the SQL Server Native Client drivers then resolved the connection and upload issue.

Extracting attachments from an Access table using Access OLE Export or SQL Blob Export

Access OLE Export 4 and SQL Blob Export 4 have added support to extract files from attachment-type columns in Microsoft Access tables.

Say we have a table named table001 with the following structure:

Attachment-type columns in Access contain sub-columns that contains details of one or more attachments stored in that row.  If we just select the table during the export process like this:

Access OLE Export / SQL Blob Export (version 4.10 onwards) will automatically detect that the files column is a attachment-type column.  It will then retrieve the FileName, FileData, and FileType subcolumns, and export the content from the FileData column using the file name value from the FileName column.

However, if you want to name the exported files differently, you will need to use the Extract items using SQL query option.  What we need to do is to enter a query to retrieve the sub-column (FileData) that contains the actual file contents.  The other useful sub-column is FileName, which stores the original file name.

We select the sub-columns by entering the column name (files), followed by a dot (.), then the sub-column name.  In the example above, to retrieve the contents of the attachment column, we enter

files.FileData

and to retrieve the original file name, we enter

files.FileName

Now if we want to, we can name the exported files using the original file name.  Enter

<filename>

as the column to use to name all the files that are exported, in the Other types section.

Access OLE Export or SQL Blob Export will then export each attachment returned by your query, and name the files using the original file names.  Of course, you can still use a different naming convention if you need to do so.

But say we want to add the ID value to the file name, as there may be duplicate file names.  We could then enter <ID>_<filename> for the file naming convention, and our exported files will contain the ID value.

We could further format the ID value to 4 digits, if we want it sorted neatly in Windows Explorer.  For e.g. instead of exported files named 1_contract.pdf, 2_invoice.pdf, 3_quotation.pdf, we could enter the naming convention value:

<ID:0000>_<filename>

and our exported files would be named 0001_contract.pdf, 0002_invoice.pdf, 0003_quotation.pdf

So if you have a ton of images that you need to export, give Access OLE Export or SQL Blob Export a try.

Connecting to SQL Server via ODBC using SQL authentication

We recently had a user who had his SQL Server hosted in a data center, and needed to extract files from his database.  He could connect to the instance remotely, but it took too long to extract the files this way.  He tried connecting to the database via another computer in the data center, but received the ‘TCP Provider: An existing connection was forcibly closed by the remote host.‘ error.

This suggests a network configuration setting issue.  Instead of getting the data center to change the server settings, we instead set up an ODBC connection and used that connection in SQL Blob Export.

Using Windows authentication to connect to the instance via ODBC was easy enough.  However, if using SQL Server authentication, the password is not stored in the ODBC settings, and the connection would still fail.

In order to connect to the SQL Server instance via ODBC using SQL Server authentication, choose the Connection string option instead.

Click on the Browse button

and select the ODBC connection to your SQL Server database.

The SQL Server ODBC connection manager will then prompt you to enter the password.

Enter the password in the provided area and click OK.  The ODBC connection string is then filled out, together with your password.

Click on the Connect button.  SQL Blob Export should now successfully connect to your SQL Server database using SQL Server authentication.

The same steps apply to our other database products that support SQL Server and ODBC connections.

If you require further assistance, you can post your questions in our support forum.

Redirecting OLE-Object linked files during export

In SQL Image Viewer 10.3, and Access OLE Export/SQL Blob Export 3.18 we added the option to redirect where to look for OLE-Object linked files during the export process.

A common issue when using OLE-Object linked files is that the location of the linked files have changed.  For e.g. you may have previously linked files from the g:\customer_invoices\ folder, but say those files have now been moved to g:\archive\customer_invoices\2018\.

Previous versions of SQL Image Viewer will fail to locate these items during the export process.  In version 10.3, you will now find a redirect button in the Image and File Options screen.

In Access OLE Export/SQL Blob Export, you will find the Redirect button in the Options screen.

Click on that button to bring up the Redirect window.  Here, you can define how the old folders map to the new folders.  For our previous example, we would enter the following:

Now during the export process, when SQL Image Viewer fails to find the files in the original folder, it will look to the redirection rules defined here and look in the new folder for the files.  It will then export the files that it finds.  You can enter multiple redirection entries, and each entry must be on a new line.

Note that the redirection entries are essentially a search/replace process.  Anything entered prior to the redirection symbol (>) is replaced with the value entered after the symbol.  Thus, the entries are not just limited to redirecting entire paths.