Collect a singleton query result as a dict with no missing values

New to Julia
, ,
1

How can I refactor the following queries so that the tests pass?

df = DataFrame(:a=>[1,2],:b=>["a","b"],:c=>[1,missing])
2×3 DataFrame
│ Row │ a     │ b      │ c       │
│     │ Int64 │ String │ Int64?  │
├─────┼───────┼────────┼─────────┤
│ 1   │ 1     │ a      │ 1       │
│ 2   │ 2     │ b      │ missing │

query 1:

d = @from i in df begin
	@where (i.a,i.b) == (1,"a")
	@select i
	@collect Dict
end
@test d = Dict(:a=>1,:b=>"a",:c=>1)
fails

query 2:

d = @from i in df begin
	@where (i.a,i.b) == (2,"b")
	@select i
	@collect Dict
end
@test d = Dict(:a=>2,:b=>"b")
fails

—edit—
I would prefer to avoid the following because it defeats the purpose of the more readable query syntax proposed above:

dd = filter(v->!ismissing(v.second),Dict(Symbol.(names(d[1,:])).=>values(d[1,:])))