The Filter activity in Azure Data Factory is used to apply a filter expression to an input array, enabling conditional filtering of data within a pipeline. This activity allows for the selection of specific data that meets certain criteria, making it a versatile tool for data processing workflows where only a subset of data is required for subsequent activities.

ADF- What is filter activity in ADF?

Definition:

In ADF, this activity is used to apply filter expression on incoming (input) array.

ADF – Filter activity implementation

Requirement:

• Use Lookup activity on SharePoint library and pull the list of files from it.
• Apply Filter activity and get only the required file from the array of the file.

Implementation:

• Add Lookup activity in ADF. From the Settings tab, select Source Dataset as SharePoint Library.
  Note: For demo purpose only, we have kept this step to select SharePoint Library. In real scenario, it can be anything.
  
• Now, we will get the list of files from this library as the output, but we need only one file. So, for that purpose we will use Filer activity now.
• Add Filter activity in ADF.
  
• Now, in the Settings tab, there are two options.
  • Items: This is the option when you choose the array/items which means the input of the Filter activity. As you can see in the screenshot below, it is the output of the earlier activity.
    
  • Condition: This property is the main property and is used to filter out the exact file we need from the array. As you can see, we have filtered out the array with specific criteria.
    
• So, this is how the filter activity works to filter out the array items.