More verbose:
julia> describe(df)
3×7 DataFrame
Row │ variable mean min median max nmissing eltype
│ Symbol Float64 Int64 Float64 Int64 Int64 DataType
─────┼────────────────────────────────────────────────────────────────
1 │ id 2.0 1 2.0 3 0 Int64
2 │ salary 4500.0 4500 4500.0 4500 0 Int64
3 │ age 30.6667 30 30.0 32 0 Int64
if you really don’t want to know anything else:
julia> describe(df, :eltype)
3×2 DataFrame
Row │ variable eltype
│ Symbol DataType
─────┼────────────────────
1 │ id Int64
2 │ salary Int64
3 │ age Int64