Fix #231

Author: Yijia-Chen

docs/src/standalonequerycommands.md

@@ -277,7 +277,8 @@ println(q1)
 
 # output
 
-3×2 DataFrame
+3×2
+DataFrames.DataFrame
 │ Row │ price   │ fruit  │
 │     │ Float64 │ String │
 ├─────┼─────────┼────────┤
@@ -287,13 +288,16 @@ println(q1)
 ```
 
 ```jldoctest
+using Query, DataFrames
+
 q2 = df |> @select(!endswith("t"), 1) |> DataFrame
 
 println(q2)
 
 # output
 
-3×3 DataFrame
+3×3
+DataFrames.DataFrame
 │ Row │ price   │ isyellow │ fruit  │
 │     │ Float64 │ Bool     │ String │
 ├─────┼─────────┼──────────┼────────┤
@@ -317,7 +321,8 @@ println(q)
 
 # output
 
-3×4 DataFrame
+3×4
+DataFrames.DataFrame
 │ Row │ name   │ amount │ cost    │ isyellow │
 │     │ String │ Int64  │ Float64 │ Bool     │
 ├─────┼────────┼────────┼─────────┼──────────┤
@@ -333,13 +338,14 @@ using Query, DataFrames
 
 df = DataFrame(fruit=["Apple","Banana","Cherry"],amount=[2,6,1000],price=[1.2,2.0,0.4],isyellow=[false,true,false])
 
-q = df |> @mutate(price = 2 * _.price + _.amount, isyellow = fruit == "Apple") |> DataFrame
+q = df |> @mutate(price = 2 * _.price + _.amount, isyellow = _.fruit == "Apple") |> DataFrame
 
 println(q)
 
 # output
 
-3×4 DataFrame
+3×4
+DataFrames.DataFrame
 │ Row │ fruit  │ amount │ price   │ isyellow │
 │     │ String │ Int64  │ Float64 │ Bool     │
 ├─────┼────────┼────────┼─────────┼──────────┤