SQL Query Return all values equal to specific value

I have the following database:
image

I have a button that I has the following script:

checkReports = system.db.runScalarQuery("SELECT Client FROM Tracker WHERE SendReminder IN ('X')")
self.getSibling("TextField").props.text = checkReports

The problem is, my SQL query is only returning the first client “A” in the textbox, and not the rest of the clients. How can I return the name of each client that has an X in their “SendReminder” column? So in this case, it would return “A, B, E”

Thank you

Use system.db.runQuery, not system.db.runScalarQuery.

runScalerQuery returns only one row.
Named queries configured as scaler will also only return one row.

Not just one row, first row and first column, i.e. a scalar value.