Why the "Non" in "ExecuteNonQuery"?

Question

I know this is not a hell of an useful question but I can't help being bugged by it.

So,
Why said method (in *Command classes) is called
ExecuteNonQuery instead of ExecuteQuery?

Aren't those SQL statements we throw at DBs, queries?

Beverie

Answer 1

Semantically, a query is something you execute to return data. You're 'querying' the database to find all the X in the Y.

If you're not expecting back results, it's not so much a query as it is a statement or command.

Kylstra

But it can be a SELECT. So why not just "myCommand.Execute()"? – Beverie

@Camilo: Because there's ExecuteReader() that will return the results of your query, or even ExecuteScalar(), for single-valued results. – Erythrocytometer

Thanks, I didn't knew of ExecuteScalar :) – Beverie

Answer 2

Not if they are INSERTs, DELETEs, CREATE TABLEs, etc.

Profession

But a method that can execute a query (i.e., SELECT) should not be called ExecuteNonQuery. That's what bothers me. – Beverie

It can execute a SELECT, but there's no point using ExecuteNonQuery with a SELECT, because it doesn't actually return a result. – Excurvature

@Camilo the DB classes don't know if you need a response explicitly telling the DB object that you don't expect anything back makes room for optimizations. You as the dev might not want anything returned by a select statement (select * into ... for one) – Accessible

Thanks Rune FS, it makes sense. – Beverie

Answer 3

I would think of it as a query is asking the database for records back. Actions that alter the data/database would not be a query.

Labanna