Question SQL_CONNECTION for SqlOperation

I'm trying to test out the SqlOperation tool. I'm not understanding something very basic. How can I define the connection I want?

Obviously the answer is, "Use the parameter 'SQL_CONNECTION'". But I don't see how to use it. It's just a text field. Why can't I select one of my Metadata Data Servers? What am I supposed to put here?

It's surely simple... but I just don't see what I need to use. Thanks for any guidance.

Currently I get errors like this:
Engine Exception during connection establishement : Unknown connection manager : SQL_CONNECTION
or
Engine Exception during connection establishement : Unknown connection manager : <Name-of-my-dataserver>
(Minor detail: "establishement" should be "establishment".)

Also note: I attached a screenshot for clarity... but it was rejected. "The file size (180916) exceeds the maximum set by the administrator." You guys should raise this limit. It was a pretty small partial screenshot.

Solved!
Thanks for the tips, that made the idea clearer. I find this aspect of the GUI unintuitive:

• When I first create the component SQLOperation the value for SQL_CONNECTION is not set. This is expected.
• When I drag in a Data Schema the SQL_CONNECTION remains unset. But it turns pink. This indicates that it's secretly set.

The end result is exactly what I want. And it's actually quite simple. It's just unintuitive for me to have this parameter indicate that it is not set as shown by the empty square brackets but also indicate that it is set using color.

It turns out that I had done all of this correctly in my earlier attempts. The problem was different. The problem was that the local runtime could not find the Oracle JDBC jar file. I had no problems connecting from the designer, so I had not thought about classpath problems in the runtime. But once I discovered the variable CORE_STACK_TRACE it was easy to identify and correct the problem.

Thanks for the assistance.