Note
Access to this page requires authorization. You can try signing in or changing directories.
Access to this page requires authorization. You can try changing directories.
Applies to: ✅ Azure Data Explorer
You can query a SQL external table just as you would query an Azure Data Explorer or a table in a KQL Database.
Azure SQL external table queries are translated from Kusto Query Language (KQL) to SQL. The operators after the external_table function call, such as where, project, count, and so on, are pushed down and translated into a single SQL query to be executed against the target SQL table.
For example, consider an external table named MySqlExternalTable with two columns x and s. In this case, the following KQL query is translated into the following SQL query.
KQL query
external_table(MySqlExternalTable)
| where x > 5
| count
SQL query
SELECT COUNT(*) FROM (SELECT x, s FROM MySqlTable WHERE x > 5) AS Subquery1