How to add current time as default value

Rails
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 S. 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

On Fri, Mar 19, 2010 at 2:44 PM, Loganathan G.
[email protected]wrote:

 t.text  :value

[email protected][email protected]
.
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.

–
Thanks:
Rajeev sharma

4

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 3 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.

5

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())