Combine duplicate rows on column1 sum column2 I have the following data.
Id      ParentId    ProductId   Quantity
215236  19297       16300319    60
215221  19297       16314611    6
215234  19297       16314670    1    &lt;- Duplicate productid
215235  19297       16314670    2    &lt;- Duplicate productid
215195  19297       16314697    20
215205  19297       16321820    75
215216  19297       16329252    10
215233  19297       16331834    9
215224  19297       16519280    40

Selecting unique records is easy. Or grouping the data on ProductId is also possible. I need a result
that only contains a unique Product Id with the same parentid and the quantities summed up.
The result should look like this.
Id      ParentId    ProductId   Quantity
215236  19297       16300319    60
215221  19297       16314611    6
215234  19297       16314670    3
215195  19297       16314697    20
215205  19297       16321820    75
215216  19297       16329252    10
215233  19297       16331834    9
215224  19297       16519280    40

The quantities of the duplicates
215234  19297       16314670    1    &lt;- Duplicate productid
215235  19297       16314670    2    &lt;- Duplicate productid

should result in
215234  19297       16314670    3
SELECT MIN(id) id,
       ParentId, 
       ProductId, 
       SUM(Quantity) Quantity
FROM [source_table_name]
GROUP BY ParentId, 
         ProductId