How to put your variables insider String Expression in Azure Data Factory

How to do string interpolation in Azure Data Factory

Background

Azure Data Factory allows us to add dynamic content in certain fields. Sometimes, we want to insert the value of variables, value of function or output of last activity into our string for dynamic content.

String Interpolation Example Illustration
String Interpolation Example Illustration

Solution

There are two approaches to achieve that.

  1. Azure Data Factory’s built-in function “concat”
  2. String Interpolation in Azure Data Factory

Azure Data Factory’s built-in function “concat”

Azure Data Factory has a built-in function “concat” which helps us concatenate string together, but this makes the dynamic content less readable.

Use built-in ‘concat’ function in Dynamic Content Modal
Use built-in ‘concat’ function in Dynamic Content Modal
Output — Azure Data Factory built-in ‘concat’ function
Output — Azure Data Factory built-in ‘concat’ function

String Interpolation in Azure Data Factory

Actually, we can do string interpolation in Azure Data Factory, which is similar to other programming languages, this approach can make our dynamic content much more to comprehend.

To achieve string interpolation, please put your variable inside “@{}”, i.e. @{your_variable_expression}. For example, it should be “@{variables(‘variable_name’)}” if your variable name is “variable_name”.

Use String Interpolation in Dynamic Content Modal
Use String Interpolation in Dynamic Content Modal
Output — Azure Data Factory String Interpolation
Output — Azure Data Factory String Interpolation

Bonus: Call functions with String Interpolation

On top of that, String Interpolation allows you to call other Azure Data Factory built-in functions inside the expression.

Use String Interpolation in other functions
Use String Interpolation in other functions
Output — String Interpolation inside other functions
Output — String Interpolation inside other functions

Medium Post: https://joeho-15265.medium.com/how-to-do-string-interpolation-in-azure-data-factory-8d2f56e192ee

Blog: https://joeho.xyz

LinkedIn: https://www.linkedin.com/in/joe-ho-0260758a