I am doing a DAX query able to retrieve a list of products installed before a certain date (COIDate) , and that have a specific ProductLine. But, it returns the same product multiple times.

I would like to know if there is a way, I'm sure there is, to write this same query, but specifying that, if a product has the same **ProductNumber** and **SerialNumber**,it's the same product and **must not be repeated in the results**, so it needs a sort of *group by(SerialNumber,ProductNumber)* or something like DISTINCT.
My background is SQL language, so the syntax needed here is different.
I tried just a distinct, like this:

```
EVALUATE 
    DISTINCT(
    SELECTCOLUMNS( 
     'Analysis Services DB',
    "SerialNumber", 'Analysis Services DB'[SerialNumber], -- 0
    "ProductNumber", 'Analysis Services DB'[ProductNumber] -- 1
    )
)  

```

And it works.
Now I need to add also these filters:

```
 'Analysis Services DB'[ProductLine] = "TW",
 'Analysis Services DB'[COIDate] <> BLANK (), format('Graphics Installed Base'[COIDate],"YYYY/MM/DD") <= "2018/12/12"

```

This is the query that I have, that I am trying to modify accordingly to what I've said above:

```
EVALUATE
    CALCULATETABLE ( SELECTCOLUMNS (
        'Analysis Services DB',
         "SerialNumber", 'Analysis Services DB'[SerialNumber], -- 0
         "ProductNumber", 'Analysis Services DB'[ProductNumber], -- 1
         "COIDate", 'Analysis Services DB'[COIDate], -- 2
         "ProductFullName", 'Analysis Services DB'[ProductFullName], -- 3
        ),
     'Analysis Services DB'[ProductLine] = "TW",
     'Analysis Services DB'[COIDate] <> BLANK (), format('Analysis Services DB'[COIDate],"YYYY/MM/DD") <= "2018/12/12"

```

**EDIT:**
What I've added:
a query with a DISTINCT and a filter, but it's missed al the other fields.
Clearly there will be another way.

```
EVALUATE
        CALCULATETABLE( 
        DISTINCT( 
            SELECTCOLUMNS( 
             'Analysis Services DB',
            "SerialNumber", 'Analysis Services DB'[SerialNumber], -- 0
            "ProductNumber", 'Analysis Services DB'[ProductNumber] -- 1
            )
    )
    , 'Analysis Services DB'[ProductLine] = "TW",
        'Analysis Services DB'[COIDate] <> BLANK (),
        format('Analysis Services DB'[COIDate],"YYYY/MM/DD") <= "2018/12/12")

```

Help me on adding the other fields, in the Select !
Thank you !