Kusto Query Language (KQL) - Distinct Operator

Basic Syntax:

The basic syntax for the distinct operator is as follows:

TableName
| distinct [Column1], [Column2], ...
    

• TableName: Specifies the name of the table you want to work with.
• Column1, Column2, ...: Specifies the columns for which you want to retrieve distinct values. If no columns are specified, it retrieves distinct rows based on all columns.

Common Use Cases:

1. Finding Unique Values:

The primary purpose of the distinct operator is to retrieve unique values from one or more columns. It helps you identify and list distinct values in your data.

MyTable
| distinct ProductCategory
    

2. Distinct Rows:

If no specific columns are specified, distinct retrieves distinct rows based on all columns. This is useful when you want to find entirely unique rows in your dataset.

MyTable
| distinct
    

3. Combining with Other Operators:

You can combine the distinct operator with other operators like project and where to perform more complex operations, such as retrieving distinct values from a subset of your data.

MyTable
| where Year >= 2020
| distinct ProductName
    

4. Counting Distinct Values:

By using count in combination with distinct, you can count the number of distinct values in a column.

MyTable
| distinct ProductCategory
| count
    

The distinct operator is a valuable tool for identifying unique values and rows within your data in Kusto Query Language. It helps in data exploration, cleansing, and analysis.