Setting MaxValue for Migrations

12 03 2013

I’ve just been using the MigratorDotNet framework for the first time. I was creating a migration that would create a new table with various new fields. One of the fields I wanted to create was to store files so therefore I wanted a varbinary(max) field. If you leave the size undeclared, it will create a varbinary(8000). The way I got around this was to create my column as follows:

Column file = new Column("BinaryFile", System.Data.DbType.Binary, int.MaxValue, ColumnProperty.NotNull);

Using the int.MaxValue gives the same result as varbinary(max). However, this doesn’t create a varbinary(max) field (at least not in SQL Server 2008 R2 which is what I am using). It creates an image field instead. This isn’t necessarily a problem, it still gives me the space I require. Importantly though, Microsoft are now advising you do not use this type in new development as it will be removed in a future version of SQL Server (see MSDN article here). We’ve weighed this up and have decided that this is not a problem for us at this time because we are developing improvements to a current system with no plans for any SQL upgrade in the future. There are also uses of the image type in other parts of the database. We have instead logged it in our technical backlog to go through and change all uses of this type at a later date. Personally, in a new project, I would not use it, just in case!

I did some searching in the hope I would find a more elegant solution (something akin to the EF Code First data annotations would have been nice) but I didn’t find anything. If anybody comes across this post, and you’ve found a nicer way to do this, please comment on here to let me know!