SQL SERVER – Iterating over Metadata with BimlScript – Notes from the Field #061

In previous articles (What is Biml and The Why of Biml), I’ve discussed Business Intelligence Markup Language (Biml) and given some examples of projects that would benefit from its use. I also demonstrated a quick way to get introduced to Biml without learning a lot of C#. As you grow in your understanding of Biml and BimlScript you will want to make your Biml files more dynamic with a programmatic metadata-driven approach. This article will build on the previous articles and add looping with metadata to build more dynamic Biml projects.

Overview

Starting where the previous article left off, I’ll demonstrate how to add a little C# to make a more automated method of metadata retrieval. If you did not walk through the other articles, I would suggest that you review them before you read this one. This article builds on the Biml in Listing 1 and lets you create multiple integration services packages from one Biml file.

Listing 1 – Semi-Automated Common Source Package Biml

Example – Automated Source Packages

This example shows you how to connect to a database and select the metadata to iterate over. Then you can create multiple SQL Server Integration Services (SSIS) packages from one Biml file. The example in the previous article manually updated the metadata and reran each Biml file. This is an effective approach, but you can build on it to create a more robust solution. Take a look at the C# code in Listing 2.

Listing 2 – C# Replacement Code

Replace the first line of code from Listing 1 with the code in Listing 2, which is an excerpt from Listing 3.

• The first line will add the namespace to the Biml file and enable the calling of functions without a fully qualified name.
• The second line creates a string variable that contains a connection string of the database with the metadata.
• The third line creates a connection object (actually an AstOleDbConnection node) that will be used by the ImportDB function.
• The forth line creates a result set with the metadata from the connection object. This object contains all of the metadata from the AdventureWorks2012 database. The ImportDB function has three parameter. The first parameter is a schema filter, and in the example the filter is on the Person schema. The second parameter is a table filter and is blank in the example, so it will be ignored. The last parameter is a list of ImportOptions, and the views have been excluded. To add more import options use the “|” followed by additional options. Example of multiple options:

ImportOptions.ExcludeForeignKey | ImportOptionsExcludeViews

The example includes an object that contains all of the metadata that you will loop over. You have to place the loop within the <Packages> node because a Biml file can only have one Packages collection. The foreach loop will create multiple <Package> nodes.

A tableName string was built below the foreach loop to reduce the code that you have to alter from the example in the previous article.

Listing 3 – Complete Code

Note: The code in listing 3 has the ConnectionString truncated to save space.

If you receive the error shown in Figure 1, it means that the tables do not exist in the stage database. To check this, add the Person filter to the table parameter in the ImportDB function and return metadata for only one table. The prior articles used this table, so it should exist.

Figure 1 – Error Message

Summary

This article added some more C# to help you refine your Biml files. I hope you can start to see the power of Biml and how it can help remove the repetitive work from your next Integration Services project.

If you want to get started with BIML with the help of experts, read more over at Fix Your SQL Server.