BQ query, not exists/joins

Question

in a BigQuery I have a table.

VM	Package
VM1	A
VM2	B
VM3	A
VM4	B
VM1	B
VM2	C
VM3	B
VM4	C

How can I get results, so all distinct VMs would be listed, but having Package column with value null (or empty, or Yes and No) if particular package not exists. I.e. I need to be listed all VMs (without duplicating), which have the package A installed, and the rest with value let say null:

VM	Package
VM1	A
VM2	null
VM3	A
VM4	null

Answer 1

You should check COUNT of package A for each VM and apply condition on the COUNT

SELECT VM, IF(COUNTIF(Package = 'A') = 0, NULL, 'A') AS Package
FROM table1
GROUP BY VM

Answer 2

Another option

select VM, 
  if('A' in unnest(array_agg(Package)), 'A', null) Package
from your_table
group by VM    

with output