Question: have this on my database

```
InspectionID  Inspection Date OdometerReading Truck Id
     1         2013-04-07       1000              1
     2         2013-04-14       2040              1
     3         2013-04-21       3000              1
    ...          .....          ....
     21         2013-05-23      1000              2
     22         2013-05-30      2000              2
     23         2013-06-07      3000              2
     24        2013-07-14       2040              3
     25         2013-07-21       3000             3
    ...          .....          ....             ....
     30         2014-05-23      15050             3
     34         2014-05-30      16032             1

```

I have selected DateStart: 2013-04-01 and DateFinished: 2014-06-01 on my datepicker, the query that should be selected is 2013-04-07 and 2014-05-30.

To summarize my question: How could i Select the First and Last Row between the Date Start and DateFinished Query so I can compute the average OdometerReading of each truck\_id on a specific time period

Answer: 
A parameter whose local name is an underscore is ignored. The caller must supply an argument, but it has no name within the function body and cannot be referred to there. It is basically a parameter placeholder that you are not going to use for anything in the body.
If I'm not mistaken this carried over from Objective-C. When you did not "use" your pointer at all in the app, you would get a warning. In Swift 2 I believe they tried to implement something similar.