问题描述
我使用PostgreSQL 9.3,Ruby 2.0,Rails 4.0.0。
I use postgresql 9.3, Ruby 2.0, Rails 4.0.0.
在阅读了关于在表上设置主键的大量问题之后,我生成并添加了以下迁移:
After reading numerous questions on SO regarding setting the Primary key on a table, I generated and added the following migration:
class CreateShareholders < ActiveRecord::Migration
def change
create_table :shareholders, { id: false, primary_key: :uid } do |t|
t.integer :uid, limit: 8
t.string :name
t.integer :shares
t.timestamps
end
end
end
我还添加了 self.primary_key = uid。
I also added self.primary_key = "uid"
to my model.
迁移成功运行,但是当我使用pgAdmin III连接到数据库时,我看到uid列是未设置为主键。我缺少什么?
The migration runs successfully, but when I connect to the DB using pgAdmin III I see that the uid column is not set as primary key. What am I missing?
推荐答案
看看。尝试执行 ALTER TABLE股东添加主键(uid);
而不在create_table块中指定primary_key参数。
Take a look at this answer. Try to execute "ALTER TABLE shareholders ADD PRIMARY KEY (uid);"
without specifying primary_key parameter in create_table block.
我建议这样编写迁移文件(以便您可以正常回滚):
I suggest to write your migration like this (so you could rollback normally):
class CreateShareholders < ActiveRecord::Migration
def up
create_table :shareholders, id: false do |t|
t.integer :uid, limit: 8
t.string :name
t.integer :shares
t.timestamps
end
execute "ALTER TABLE shareholders ADD PRIMARY KEY (uid);"
end
def down
drop_table :shareholders
end
end
UPD:有一种自然的方法(),但仅使用int4类型:
UPD: There is natural way (found here), but only with int4 type:
class CreateShareholders < ActiveRecord::Migration
def change
create_table :shareholders, id: false do |t|
t.primary_key :uid
t.string :name
t.integer :shares
t.timestamps
end
end
end
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