The Art of SQL Server FILESTREAM - Red Gate Software

Chapter 2: Getting Started with FILESTREAMFILESTREAM and triggersJust like other columns, FILESTREAM columns are accessible from within DMLtriggers. The FILESTREAM columns can be accessed from a trigger in the same way asa regular VARBINARY(MAX) column. DML triggers get fired even when modifying theFILESTREAM data using Win32 I/O streaming.It is not good practice to print debug information from a trigger. However, for thepurpose of showing that the FILESTREAM columns are accessible from a trigger, we'llcreate an INSERT trigger that prints the size of the FILESTREAM data value beinginserted (Listing 2-22).CREATE TRIGGER TGR_Items ON dbo.ItemsAFTER INSERTASBEGINDECLARE @size INTSELECT @size = DATALENGTH(ItemImage)FROM INSERTEDPRINT 'FILESTREAM Size :' + STR(@size)ENDListing 2-22:An INSERT trigger that prints the size of the FILESTREAM data value being inserted.Now we'll insert a new record into the FILESTREAM column of the Items table using thescript in Listing 2-23.-- Insert the data to the tableINSERT INTO Items( ItemID ,ItemNumber ,ItemDescription ,ItemImage)79