Hello there,Can you do multiple SQL stamentents inside a single SQL Advanced?Example:DELETE {Student}:SELECT * FROM {STUDENT};My goal is that the output shows if the list is Empty or not.
Hello @Rui Rodrigues , You sure can. I have tried this to confirm. I have a test entity with 1 row. I have tried 2 pairs of SQL queries.
first case
SELECT * FROM {Book_Details};
DELETE FROM {Book_Details} WHERE {Book_Details}.[Id] = 1;
in this case, first the select query is run and then delete query, thus giving 1 row in output.
second case
in this case, first the delete query is run and then select query, thus giving 0 rows in output.
So, we can run multiple SQL statements inside a single SQL Advanced, but the output will get affected by their sequence
Yes you can do that.
It is easy, and even a best practice to do bulk operations, like a delete in an advanced query
But i suggest make an aggregate to check if {Book_details} is really empty.
As others said, you can, but I'd consider it bad practice. There's no advantage over splitting the query in two. The code will be more difficult to read, as a single node contains two different concepts.
Also, a DELETE FROM {Student} will either delete all records from Student, or none. Using a SELECT * (btw, never use SELECT * in an OS SQL! At the very least use SELECT {Student}.*!) will either find no records, or all records, but more likely in case of an error the SELECT isn't executed at all, as the database will throw an exception. And why fetch all records if you just want to know whether there are any records?
Thank you Kilian.My goal was to reduce the overhead between SQL queries gaining a margin on the duration.Congratz on the award at One - Lisbon
I think the overhead would be negligeable, especially because a) if you have a lot of records to delete, that will take the bulk of the time and b) you probably won't very often execute such a delete all records. Sounds a bit like premature optimization :).