If text is selected, the "Run" button at the top should "Run Selection" - or maybe we just add a "Run Selection" button to the toolbar

[alexjpwalker]

Problem to Solve

1. Select some text in a query file
2. Hit "Run" in the toolbar

Expected Output

The selection is run

Actual Output

The whole file is run, leading to unexpected behaviour (but no damage, usually; you can just rollback the transaction)