Power Query - Inserting rows into SQL gets repeated and inserts 3 times

[s1]

I have a simple M script in a Data Flow. When I run a query with INSERT in SQL, it adds the row as I would expect. But I perform the same thing in my Data Flow, and just refreshing the preview causes it to add 3 rows for each row that is added in my insert statement.

Is there any way to make it only run once? Is there any way to make it perform a check before inserting so that even though it writes 3 times, only one gets saved by the SQL database?

let
  query = "INSERT INTO ...",
  dbWrite = Sql.Database(server, database, [Query=query, CreateNavigationProperties=false]),
in
  dbWrite

[lbendlin]

Do. Not. Do. That.

Power Query was never designed to write into anything except a Semantic Model.

There is NO guarantee that your Power Query will run only once.  Most of the time it will not.

Chris Webb's BI Blog: Why Does Power BI Query My Data Source More Than Once? (crossjoin.co.uk)

Repeat: Do. Not. Do. That.

[s1]

If I shouldn't take this approach, is there any other way to save Dataflow Power Query results to a SQL database?

[lbendlin]

Don't use either Dataflows or Power Query.  Use a proper ETL tool like SSIS, or Informatica.  There is no need to drag Power BI into your data movement process.

If you are planning to use Fabric as a data storage this story becomes slightly different. Dataflows Gen 2 are designed to write into the Fabric lakehouse etc.