Better syntax support for SQL auto translation.

Currently SQL auto translation uses the following syntax.
```
SELECT * INTO ${citiesTable} FROM cities WHERE longitude BETWEEN -80 and -79;
```
Is it possible to support specifying output in comment? Take the following code as an example. The benefit is that the same SQL code can be copy/pasted into other SQL IDE to run without any modification.
```
-- output = citiesTable
SELECT * FROM cities WHERE longitude BETWEEN -80 and -79;
```