how to add current time as default value

rubyonrails-talk
1

hi all,

by using timestamps we can create created_at and updated_on columns to our tables. But i dont wnat the columns in my table and i want to add my own column which datatype is timestamp and that must take current_timestamp or now as default value.

how to do it

re

2

Rajkumar Surabhi wrote:

hi all,

by using timestamps we can create created_at and updated_on columns to our tables. But i dont wnat the columns in my table and i want to add my own column which datatype is timestamp and that must take current_timestamp or now as default value.

how to do it

re

Since we cannot specify the now() function in the :default option in the migration file, we can achieve this requirement using the following:

# Sample code class Samples < ActiveRecord::Migration   def self.up     create_table :system_settings do |t|       t.text :value       t.string :type       t.timestamp :created_time     end       execute "ALTER TABLE system_settings ALTER created_time SET DEFAULT now()"   end

  def self.down   end end

3

Time.now

4

If Loganathan's answer does not work, try this:

I had to use

execute "ALTER TABLE system_settings ALTER created_time SET DEFAULT CURRENT_TIMESTAMP"

(instead of NOW())

5

Okay, so it turns out that does not work either. Here is the actual syntax:

  execute "ALTER TABLE tablename CHANGE column_name column_name TIMESTAMP DEFAULT CURRENT_TIMESTAMP"

You have to put the column name in twice as well as specify the datatype again.

Also, you may be wondering why I am responding to a 7 year old question... I came across it on google and there was NOTHING else out there to help with this issue. Yes, I know Rails creates timestamps for you. However, when you are polling a database that can have information entered from other sources, it is useful to be able to do this.