SQLite How to sum columns based on one one column and group based on a different column

Question

For example, table TableQ looks like this:

Item	Price	Tag
Item A	2	X
Item A	4	Y
Item B	1	Z

I want my output to be like this:

Item	Price	Tag
Item A	6	X
Item A	6	Y
Item B	1	Z

When I try

select distinct * from TableQ as Q1 left join ( select sum(Q2.Price) as PriceSum from TableQ as Q2 )

I get

Item	Price	Tag	PriceSum
Item A	2	X	7
Item A	4	Y	7
Item B	1	Z	7

Answer 1

Since version 3.25.0 (2018-09-15) SQLite supports window functions:

SELECT Item,
       SUM(Price) OVER (PARTITION BY Item) AS Price,
       Tag 
FROM TableQ;

See the demo.