Question

What I need to do is I want to be able to create a table with dynamic columns, retrieving column name and its data type out of a hash.

Please take the code snippet below for example:

COLUMNS =  { :column1 => 'integer',
                :column2 => 'string',
                :column3 => 'string',
                :column4 => 'date'
                }

In the static way, I could do like this:

create_table :details do |t|
  t.integer column1
  t.string column2
  t.string column3
  t.date column4
  t.timestamps
end

But, you know, that looks a bit hard-coded, and I’m not happy with that.

My idea is to make it more like:

create_table :details do |t|

  COLUMNS.each_pair do |key,value|
    #to define each column and its data type
    t[value] key
  end

  t.timestamps  
end

Unfortunately, it doesn’t seem to work for me the way I want.

Answer 1

t.integer is calling a method on t, not doing an array index, so have you tried instead calling t.__send__(value, key) ?