I’ve got a migration that adds a column then sets the value for one of
the records:
def self.up
add_column :publish_property_lists, :preview_page_header, :string
if p = PublishPropertyList.find(:first, :conditions =>
“default_properties IS TRUE”)
p.update_attribute :preview_page_header, “Preview Your Video
Entry”
end
end
However after running the migration, preview_page_header is still null
in the database. I thew a puts statement inside the if to make sure
it’s getting there, and it is. So why isn’t the record being updated?
Pat
On 3/13/07, Pat M. [email protected] wrote:
However after running the migration, preview_page_header is still null
in the database. I thew a puts statement inside the if to make sure
it’s getting there, and it is. So why isn’t the record being updated?
Pat
It gets weirder (for me). I thought maybe it was a transaction issue,
so I split the migration out into two separate steps. The first
migration adds the column. The second migration finds the record and
updates it. I took the conditional out of the second migration as
well, so I know that it’s finding and updating a record. Still, the
database doesn’t reflect that.
If I create a record with attributes, it’s fine. I just can’t update
it from a migration. What gives?
Pat
On 3/13/07, Pat M. [email protected] wrote:
end
migration adds the column. The second migration finds the record and
updates it. I took the conditional out of the second migration as
well, so I know that it’s finding and updating a record. Still, the
database doesn’t reflect that.
If I create a record with attributes, it’s fine. I just can’t update
it from a migration. What gives?
Pat
Okay looking at the logs, the migration updates all the existing
values and commits it. So say the record has the name “foo”, the logs
show:
PublishPropertyList Load (0.000552) SELECT * FROM
publish_property_lists WHERE (default_properties IS TRUE) LIMIT 1
SQL (0.000152) BEGIN
PublishPropertyList Update (0.000452) UPDATE
publish_property_lists SET name = ‘foo’ WHERE id = 1
SQL (0.000098) COMMIT
Obviously that’s not very helpful…I don’t need to update the record
with the attributes it already has, but rather need to update its new
attributes. I’m really confused here.
Pat
On Mar 13, 2007, at 4:22 PM, Pat M. wrote:
I’ve got a migration that adds a column then sets the value for one of
the records:
def self.up
add_column :publish_property_lists, :preview_page_header, :string
PublishPropertyList.reset_column_information
Pat
ActiveRecord needs to be told to take a new look at the table since
you changed it.
-Rob
Rob B. http://agileconsultingllc.com
[email protected]
On 3/13/07, Pat M. [email protected] wrote:
end
migration adds the column. The second migration finds the record and
updates it. I took the conditional out of the second migration as
well, so I know that it’s finding and updating a record. Still, the
database doesn’t reflect that.
If I create a record with attributes, it’s fine. I just can’t update
it from a migration. What gives?
Pat
It turns out I need to add
PublishPropertyList.reset_column_information
Now that behavior makes a little bit of sense when I do the full
migration (0-final). When I create the record, Rails loads
PublishPropertyList into the namespace. When I go to update it later
on, it has it cached along with the columns. So I have to reset the
column info.
It’d make a lot more sense if Rails threw a method missing error,
because that’s essentially what it thinks is going on. Oh well.
Pat
On Mar 13, 2007, at 4:45 PM, Pat M. wrote:
Entry"
Pat
My previous email is still valid (reset_column_information), but you
probably also have to make the condition valid from the point of view
from SQL.
Try this:
p = PublishPropertyList.find(:first, :conditions =>
[“default_properties = ?”, true])
This should work for any database regardless of whether booleans are
modeled as 0/1 or true/false.
In any case the SQL fragment “where default_properties IS TRUE” is
quite likely not equivalent to “where default_properties = 1” or
“where default_properties = true” (note “=” rather than “IS”).
-Rob
Rob B. http://agileconsultingllc.com
[email protected]