Friday, September 26, 2014

Exploring BIML

Getting Started

I attended Varigence’s BIML Workshop last year prior to the PASS conference and got to learn a little BIML while seeing what it can do. Recently, I realized that I had a job to do that required applying the same SSIS ETL to several different sets of tables in our system. I figured this would be a great time to put some of that BIML into use.

To get started, you’ll need either the BIDS Helper add-on or a copy of Varigence’s Mist. While Mist is an excellent tool, it’s also priced towards the people who are really working with BIML and not targeted at those who aren’t quite ready to justify the cost. ($249/month or $3999 at the time I’m writing this – worth it if you use a lot of BIML, but not for everyone)

I made sure my BIDS Helper bits were up to date, started a new SSIS Project, and added a new BIML file by right-clicking the project and selecting “Add New BIML File”. After that I followed a couple of excellent walkthroughs and tutorials to get me started and refresh my memory. To name a couple of sources:



1. Actually getting my connection string correct. I don’t often type in connection strings so hit the website for SQL OLEDB connections. That told me to use this format for my connect strings:


Regardless of what I tried, this refused to connect as expected. I eventually changed back to the older syntax and that worked:

Provider=SQLNCLI11;Data Source=myServerAddress;Initial Catalog=myDataBase;Integrated Security=True;

Not a huge deal, but this was giving me fits with my connections with either security issues or having to specify DB Names in my code.


2. Next up – not knowing C# or BIML very well. Nothing for this except time and practice. :-)  I got better along the way, slowly catching things as I typed them in and having some feel for what would happen.


3. For some reason, my Intellisense completely stopped working at one point. It worked for everything prior to when I added my “import” lines for various namespaces, but anything after that wouldn’t work at all. I got around this a little by using the BimlScript Editor online to check some code, but obviously this doesn’t work when you’re importing local columns. I never did get this working but also haven’t tried to reproduce it with a new project.

Update: It seems that if I move my @ Import statements before I open the first BIML tag in the XML, my intellisense works again. Putting the statements within the Biml section is perfectly valid, but putting them at the top/beginning of the file before I start writing Biml makes a lot more sense and results in Intellisense working again. This would have made my life easier.


4. The last major challenge this time through was trying to get BIML to generate a logical “AND” in the SSIS expression I wanted to use. I typed it in, used “&&” for my AND statement, and checked syntax. I repeatedly got errors about syntax. The first time around, I figured my expression might be too long. It was and I broke it apart only to get the same error. I looked at the string generated using some MessageBox.Show() hacks and it looked okay. I finally came across a tip indicating that BIML doesn’t work well with the “&” character. The suggestion was to replace that with “&” whenever you wanted to output an ampersand as part of the expression. This worked well and my package was generated.



I still need to tweak my package. I have more tables to import from a different source on the same server, but targeting a single database on my destination server. I need to figure out tiers and included files to better reuse and organize code. I’d love to get the correct connections going so BIML and SSIS read the correct column data types, especially when it comes to BLOB data columns. I need to rework some of the package components to better adhere to best practices. Overall it’s been an interesting ride trying to figure these things out and while it may not have saved time with this particular project, I’ll be able to use the lessons learned for my next project.