Level Up Your Biml: Best Practices and Coding Techniques (SQLSaturday Denver)

Level Up Your Biml:
Best Practices and Coding Techniques
Cathrine Wilhelmsen

Cathrine Wilhelmsen - contact@cathrinewilhelmsen.net
Session Description
Is your Biml solution starting to remind you of a bowl of tangled spaghetti code?
Good! That means you are solving real problems while saving a lot of time. The
next step is to make sure that your solution does not grow too complex and
confusing – you do not want to waste all that saved time on future maintenance!
Attend this session for an overview of Biml best practices and coding techniques.
Learn how to centralize and reuse code with Include files and the CallBimlScript
method. Make your code easier to read and write by utilizing LINQ (Language-
Integrated Queries). Share code between files by using Annotations and
ObjectTags. And finally, if standard Biml is not enough to solve your problems, you
can create your own C# helper classes and extension methods to implement
custom logic.
Start improving your code today and level up your Biml in no time!

Cathrine Wilhelmsen
@cathrinew
cathrinew.net
Data Warehouse Architect
Business Intelligence Developer

You…
…?
Know basic Biml and BimlScript
Completed BimlScript.com lessons
Created a staging environment

Code Management
…the next 75 minutes…
C# Classes and MethodsPractical Biml Coding

Biml and
BimlScript

Biml vs. BimlScript
Generate, control and
manipulate Biml with C#
XML Language
"Just plain text"

Biml
Biml is an XML language – it's just plain text
Easy to read and write – but can be verbose
You probably don't want to write 50000 lines of
Biml code manually...?

Generating Biml
You can use any tool to generate Biml for you:
• Text editor macros
• Excel
• PowerShell
• T-SQL
…but the recommended tool is BimlScript :)

What is BimlScript?
Extend Biml with C# or VB code blocks
Import database structure and metadata
Loop over tables and columns
Expressions replace static values
Allows you to generate, control and manipulate Biml code

BimlScript Code Nuggets
<# … #> Control Nuggets (Control logic)
<#= … #> Text Nuggets (Returns string)
<#@ … #> Directives (Compiler instructions)
<#+ … #> Class Nuggets (Create C# classes)

BimlScript Syntax
<# var con = SchemaManager.CreateConnectionNode(...); #>
<# var metadata = con.GetDatabaseSchema(); #>
<Biml xmlns="http://schemas.varigence.com/biml.xsd">
<Packages>
<# foreach (var table in metadata.TableNodes) { #>
<Package Name="Load_<#=table.Name#>"></Package>
<# } #>
</Packages>
</Biml>

BimlScript Syntax: Import metadata
<Packages>
<# } #>
</Packages>
</Biml>

BimlScript Syntax: Loop over tables
<Packages>
<# } #>
</Packages>
</Biml>

BimlScript Syntax: Replace static values
<Packages>
<# } #>
</Packages>
</Biml>

How does it work?

Yes, but how does it work?

Yes, but how does it actually work?
<# } #>
<Package Name="Load_Customer"></Package>
<Package Name="Load_Product"></Package>
<Package Name="Load_Sales"></Package>

Biml Tools
Comparison

What do you need?

BimlExpress
Free add-in for Visual Studio
Code editor with syntax highlighting and Biml Intellisense
More frequent updates than BIDS Helper
varigence.com/bimlexpress

BimlOnline
Free browser-based Biml editor
Code editor with Biml and C# Intellisense
Reverse-engineer from SSIS to Biml
bimlonline.com

BimlStudio
Licensed full-featured development environment for Biml
Visual designer and metadata modeling
Full-stack automation and transformers
varigence.com/bimlstudio

Biml Tools Comparison
Free
Biml Intellisense
Preview BimlScript
Free
Full Intellisense
Logical View
Licensed
Full IDE
SSAS+++

Code
Management

Don't Repeat Yourself
Move common code to separate files
Centralize and reuse in many projects
Update code once for all projects
1. Tiered Biml Files
2. Include Files
3. CallBimlScript

Tiered Biml Files

Tiered Biml Files
Split Biml code in multiple files to:
• Solve logical dependencies
• Build solutions in multiple steps behind the scenes
Specify the tier per file by using the template directive:
<#@ template tier="2" #>

Tiered Biml Files
Biml is compiled step-by-step from lowest to highest tier
• Biml files are implicitly tier 0
• BimlScript files are implicitly tier 1
In each tier, objects are added to the in-memory RootNode
Higher tiers can use objects from lower tiers

What is this RootNode?
When working with Biml, the
<Biml> root element contains
collections of elements:
When working with BimlScript,
the RootNode object contains
collections of objects:
<Biml>
<Connections>...</Connections>
<Databases>...</Databases>
<Schemas>...</Schemas>
<Tables>...</Tables>
<Projects>...</Projects>
<Packages>...</Packages>
</Biml>

Tiered Biml Files: Behind the Scenes
<Connections>...</Connections>
<Packages>...</Packages>
<Package>...</Package>

Tiered Biml Files: Behind the Scenes

How do you use Tiered Biml Files?
1. Create Biml files with specified tiers
2. Select all the tiered Biml files
3. Right-click and click Generate SSIS Packages
1
2
3

Include Files

Include Files
Include common code in multiple files and projects
Can include many file types: .biml .txt .sql .cs
Use the include directive
<#@ include file="CommonCode.biml" #>
The directive will be replaced by the included file
Works like an automated Copy & Paste

Global Include Files

Use the global directive
<#@ global #>
Use instead of adding include directive to all files to
• Create global variables
• Include code files
• Make VB default language

Specify directive attributes to control global include files
<#@ global
order="1"
location="top"
active="true"
applytocallbimlscript="false" #>

How do you use Global Include Files?
1. Create Global Include File
2. Select Biml files and Global Include File
3. Right-click and click Generate SSIS Packages
1
2
3

CallBimlScript

CallBimlScript
Works like a parameterized include (or stored procedure)
File to be called (callee) specifies accepted parameters:
<#@ property name="Parameter" type="String" #>
File that calls (caller) passes parameters:
<#=CallBimlScript("Common.biml", Parameter)#>

CallBimlScriptWithOutput

Callee specifies custom output object:
<# CustomOutput.BimlComment = "Comment"; #>
Caller defines, passes and uses output object:
<# dynamic outObj; #>
<#=CallBimlScriptWithOutput("CommonCode.biml",
out outObj)#>
<#=outObj.BimlComment#>

use CustomOutput

How does this actually work?

Passing code
between files

Annotations and ObjectTags
Annotations and ObjectTags are Key / Value pairs
Use them to pass code between Biml files
Annotations: String / String
ObjectTags: String / Object

Annotations
Create annotations:
<OleDbConnection Name="Destination" ConnectionString="…">
<Annotations>
<Annotation Tag="Schema">AW2014</Annotation>
</Annotations>
</OleDbConnection>
Use annotations:
RootNode.OleDbConnections["Destination"].GetTag("Schema");

ObjectTags
Create ObjectTags:
RootNode.OleDbConnections["Destination"].ObjectTag["Filter"]
= new List<string>{"Product","ProductCategory"};
Use ObjectTags:
RootNode.OleDbConnections["Destination"].ObjectTag["Filter"];

LINQ

LINQ (Language-Integrated Query)
One language to query:
SQL Server Databases
Datasets
Collections
Two ways to write queries:
SQL-ish Syntax
Extension Methods

LINQ Extension Methods
Sort
OrderBy, ThenBy
Filter
Where, OfType
Group
GroupBy
Aggregate
Count, Sum
Check Collections
All, Any, Contains
Get Elements
First, Last, ElementAt
Project Collections
Select, SelectMany

LINQ Extension Methods Example
var numConnections = RootNode.Connections.Count()
foreach (var table in RootNode.Tables.Where(…))
if (RootNode.Packages.Any(…))

LINQ Extension Methods Example
foreach (var table in RootNode.Tables.Where(…))
if (RootNode.Packages.Any(…))
But what do you put in here?

Lambda Expressions
"A lambda expression is an anonymous
function that you can use to create
delegates or expression tree types"

Lambda Expressions
…huh? o_O

Lambda Expressions
table => table.Name == "Product"

Lambda Expressions
The arrow is the lambda operator

Lambda Expressions
Input parameter is on the left side

Lambda Expressions
Expression is on the right side

LINQ and Lambda
Chain LINQ Methods and use Lambda Expressions
for simple and powerful querying of collections:
.Where(table => table.Schema.Name == "Production")
.OrderBy(table => table.Name)

LINQ: Filter collections
Where()
Returns the filtered collection with all elements that meet the criteria
RootNode.Tables.Where(t => t.Schema.Name == "Production")
OfType()
Returns the filtered collection with all elements of the specified type
RootNode.Connections.OfType<AstExcelOleDbConnectionNode>()

LINQ: Sort collections
OrderBy()
Returns the collection sorted by key…
RootNode.Tables.OrderBy(t => t.Name)
ThenBy()
…then sorted by secondary key
RootNode.Tables.OrderBy(t => t.Schema.Name)
.ThenBy(t => t.Name)

OrderByDescending()
Returns the collection sorted by key…
RootNode.Tables.OrderByDescending(t => t.Name)
ThenByDescending()
…then sorted by secondary key
RootNode.Tables.OrderBy(t => t.Schema.Name)
.ThenByDescending(t => t.Name)

Reverse()
Returns the collection sorted in reverse order
RootNode.Tables.Reverse()

LINQ: Group collections
GroupBy()
Returns a collection of key-value pairs where each value is a new collection
RootNode.Tables.GroupBy(t => t.Schema.Name)

LINQ: Aggregate collections
Count()
Returns the number of elements in the collection
RootNode.Tables.Count()
RootNode.Tables.Count(t => t.Schema.Name == "Production")

Sum()
Returns the sum of the (numeric) values in the collection
RootNode.Tables.Sum(t => t.Columns.Count)
Average()
Returns the average value of the (numeric) values in the collection
RootNode.Tables.Average(t => t.Columns.Count)

Min()
Returns the minimum value of the (numeric) values in the collection
RootNode.Tables.Min(t => t.Columns.Count)
Max()
Returns the maximum value of the (numeric) values in the collection
RootNode.Tables.Max(t => t.Columns.Count)

LINQ: Check collections
All()
Returns true if all elements in the collection meet the criteria
RootNode.Databases.All(d => d.Name.StartsWith("A"))
Any()
Returns true if any element in the collection meets the criteria
RootNode.Databases.Any(d => d.Name.Contains("DW"))

LINQ: Check collections
Contains()
Returns true if collection contains element
RootNode.Databases.Contains(AdventureWorks2014)

LINQ: Get elements
First()
Returns the first element in the collection (that meets the criteria)
RootNode.Tables.First()
RootNode.Tables.First(t => t.Schema.Name == "Production")
FirstOrDefault()
Returns the first element in the collection or default value (that meets the criteria)
RootNode.Tables.FirstOrDefault()
RootNode.Tables.FirstOrDefault(t => t.Schema.Name == "Production")

LINQ: Get elements
Last()
Returns the last element in the collection (that meets the criteria)
RootNode.Tables.Last()
RootNode.Tables.Last(t => t.Schema.Name == "Production")
LastOrDefault()
Returns the last element in the collection or default value (that meets the criteria)
RootNode.Tables.LastOrDefault()
RootNode.Tables.LastOrDefault(t => t.Schema.Name == "Production")

LINQ: Get elements
ElementAt()
Returns the element in the collection at the specified index
RootNode.Tables.ElementAt(42)
ElementAtOrDefault()
Returns the element in the collection or default value at the specified index
RootNode.Tables.ElementAtOrDefault(42)

LINQ: Project collections
Select()
Creates a new collection from one collection
A list of table names:
RootNode.Tables.Select(t => t.Name)
A list of table and schema names:
RootNode.Tables.Select(t => new {t.Name, t.Schema.Name})

LINQ: Project collections
SelectMany()
Creates a new collection from many collections and merges the collections
A list of all columns from all tables:
RootNode.Tables.SelectMany(t => t.Columns)

Error Handling
and Debugging

Error Handling

Biml Validation
Biml has built-in ValidationReporter
Create custom warnings and errors
Especially useful in teams

Biml Validation: ValidationReporter
Build will succeed on Warning
<# ValidationReporter.Report(Severity.Warning, "Oops!"); #>
Build will fail on Error, but not immediately
<# ValidationReporter.Report(Severity.Error,"Uh-oh!"); #>
Build will immediately fail on Fatal Error
<# ValidationReporter.Report(Severity.Fatal, "PANIC!"); #>

Debugging

Biml Debugging
Include DebugUtilities.cs in your project
Reference code file
<#@ code file="DebugUtilities.cs" #>
Get all property values on Biml objects
<#=table.GetAllPropertyValues()#>

How do you debug Biml?

Classes
and Methods

C# Classes and Methods
BimlScript and LINQ not enough?
Need to reuse C# code?
Create your own classes and methods!

C# Classes and Methods
public static class HelperClass {
public static bool AnnotationTagExists(AstNode node, string tag) {
return (node.GetTag(tag) != "");
}
}

C# Classes and Methods: Class
}
}

C# Classes and Methods: Method
}
}

C# Classes and Methods: Logic
}
}

Where do you put your C# code?
Inline Code Blocks
<#+ ... #>
Included Biml Files with Code Blocks
<#@ include file="CodeBlock.biml" #>
Code Files
<#@ code file="Code.cs" #>

Inline Code Blocks
<#+ ... #>

Inline Code Blocks
<# foreach (var table in RootNode.Tables) { #>
<# if (HelperClass.AnnotationTagExists(table, "SourceSchema")) { #>
...
<# } #>
<# } #>
</Biml>
<#+
return (node.GetTag(tag) != "") ? true : false;
}
}
#>

<#+ ... #>

<#@ include file="HelperClass.biml" #>
...
<# } #>
<# } #>
</Biml>
<#+
}
}
#>

Code Files

Code Files
<#@ code file="HelperClass.cs" #>
...
<# } #>
<# } #>
</Biml>
}
}

How do you create C# classes
and methods?

Extension
Methods

Extension Methods
"Make it look like the method belongs to
an object instead of a helper class"

Extension Methods: From this…
...
<# } #>
<# } #>
</Biml>
}
}

Extension Methods: …to this
...
<# } #>
<# } #>
</Biml>
public static bool AnnotationTagExists(this AstNode node, string tag) {
}
}

Extension Methods: …to this
<# if (table.AnnotationTagExists("SourceSchema")) { #>
...
<# } #>
<# } #>
</Biml>
}
}

Extension Methods: …to this :)
<# foreach (var table in RootNode.Tables.Where(t =>
t.AnnotationTagExists("SourceSchema")) { #>
...
<# } #>
<# } #>
</Biml>
}
}

How do you create C#
extension methods?

Code Management
…the past 75 minutes…
C# Classes and MethodsPractical Biml Coding

Where can you learn more?

Get things done
Start small
Start simple
Start with ugly code
Keep going
Expand
Improve
Deliver often

Biml on Monday…
…BimlBreak the rest of the week ☺

@cathrinew
cathrinew.net
linkedin.com/in/cathrinewilhelmsen
hi@cathrinew.net
slideshare.net/cathrinewilhelmsen
Biml resources and references:
cathrinew.net/biml

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