If you need to trigger one Marketing Cloud email to multiple recipients in a single REST API call, here’s how you do it:
Request a token (OAuth 2.0)
Trigger one email to multiple recipients:
Reference:
Clearing a Data Extension with a SQL Query
If you ever need an automated way to clear a data extension, you can simply use a SQL query that does an overwrite. The query doesn’t need a from clause if you specify any required columns in the target.
For example, if EmailAddress is required in the target data extension, simply set the value to null and add an alias: