Rails Console中的数据库值为[“”，“ 5”，“ 1”，“ 2”，“ 8”，“ 6”，“ 9”]，显示为“ [\\” \\”，\\“ 5 \\”， \\“ 1 \\”，\\“ 2 \\”，\\“ 8 \\”，\\“ 6 \\”，\\“ 9 \\”]“？

Question

Database value is

["", "5", "1", "2", "8", "6", "9"] 

But in Rails console it showing as:

"[\"\", \"5\", \"1\", \"2\", \"8\", \"6\", \"9\"]" 

Any solution to show it as same as the array?

Answer 1

Looks like you column is saved as json

[15] pry(main)> JSON.parse("[\"\", \"5\", \"1\", \"2\", \"8\", \"6\", \"9\"]")
=> ["", "5", "1", "2", "8", "6", "9"]

you can use serialize :name_of_that_column, Array so it get parsed when called from db

you can check http://api.rubyonrails.org/classes/ActiveRecord/AttributeMethods/Serialization/ClassMethods.html f

Answer 2

If what you want do is getting array of integers from string, use scan and regular expression.

For example,

   pry(main)> str = "[\"\", \"5\", \"1\", \"2\", \"8\", \"6\", \"9\"]"
    => "[\"\", \"5\", \"1\", \"2\", \"8\", \"6\", \"9\"]"
   pry(main)> str.scan(/\d+/)
    => ["5", "1", "2", "8", "6", "9"]