Join data from multiple log types stored in the same table using the Kusto Query Language (KQL).

In Azure Monitor (formerly known as Azure Log Analytics or Azure Application Insights), you can join data from multiple log types stored in the same table using the Kusto Query Language (KQL). This allows you to combine and analyze data from different sources efficiently. Here's a step-by-step guide with a query example:

Step 1: Open Azure Monitor (Log Analytics)

1. Navigate to the Azure Portal (https://portal.azure.com/).
2. In the left-hand menu, click on "Monitor."

Step 2: Select the Log Analytics Workspace

1. In the "Monitor" menu, click on "Logs" to open the Log Analytics workspace.

Step 3: Write a Query to Join Data from Multiple Log Types

In this scenario, let's assume you have two log types called [LogTypeA] and [LogTypeB], both of which are stored in the same table called [MyLogs]. You want to join and combine data from both log types based on a common field. Here's how you can write a query to do that:

let LogTypeAData = 
    MyLogs
    | where LogType == "LogTypeA"
    | project CommonField, FieldA;

let LogTypeBData =
    MyLogs
    | where LogType == "LogTypeB"
    | project CommonField, FieldB;

LogTypeAData
| join kind=inner (
    LogTypeBData
) on CommonField
| project CommonField, FieldA, FieldB
        

In this query:

• let is used to define two subqueries (LogTypeAData and LogTypeBData) that filter data from MyLogs based on the log types (LogTypeA and LogTypeB) and project relevant fields.
• join is used to join the data from both log types (LogTypeAData and LogTypeBData) on the common field (CommonField in this case).
• Finally, the project operator is used to select the fields you want to include in the query result, which may include the common field and fields specific to each log type (FieldA and FieldB).

Step 4: Run the Query

After writing your query, click the "Run" button to execute it.

Step 5: View Results

The query results will be displayed in a tabular format below the query editor. These results will contain data from both LogTypeA and LogTypeB joined based on the common field (CommonField).

Step 6: Save or Export Data

You can save or export query results for further analysis or reporting. Use options like "Export," "Save," or "Add to Workbook" to perform these actions.

By adapting the query based on your specific log types, fields, and the common field you want to use for joining, you can effectively join data from multiple log types stored in the same table in Azure Monitor.