table-relationships | 易学教程

Importing/Exporting Relationships in MS Access

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问题 I have a couple of mdb files with the exact table structure. I have to change the primary key of the main table from autonumber to number in all of them, which means I have to: Drop the all the relationships the main table has Change the main table Create the relationships again,... for all the tables. Is there any way to export the relationships from one file and importing them to all the rest? I am sure this can be done with some macro/vb code. Does anyone has an example I could use? Thanks

Multi level associations in rails

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I am creating an application to track football teams through out the season. but i am stuck on the design of the database. One fixture has a home team and an away team. I have created a fixture model which has two foreign keys- home_team and away_team but I cant get the association to work right. any ideas? Each fixture belongs to a league. The simple answer is: class Fixture < ActiveRecord::Base belongs_to :home_team, :class_name => "Team", :foreign_key => :home_team belongs_to :away_team, :class_name => "Team", :foreign_key => :away_team end class Team < ActiveRecord::Base has_many :fixtures

Multi level associations in rails

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问题 I am creating an application to track football teams through out the season. but i am stuck on the design of the database. One fixture has a home team and an away team. I have created a fixture model which has two foreign keys- home_team and away_team but I cant get the association to work right. any ideas? Each fixture belongs to a league. 回答1: The simple answer is: class Fixture < ActiveRecord::Base belongs_to :home_team, :class_name => "Team", :foreign_key => :home_team belongs_to :away