更新时间:2023-11-23 14:50:46
在使用 MySQL 时,可以调用 change_column
,但必须重复列类型(只需从其他迁移):
When using MySQL, you can call change_column
, but you have to repeat the column type (just copy and paste it from your other migration):
def up
change_column :your_table, :some_column, :integer, after: :other_column
end
或者,如果您必须对一个表中的多个列重新排序:
Or if you have to reorder multiple columns in one table:
def up
change_table :your_table do |t|
t.change :some_column, :integer, after: :other_column
# ...
end
end
change_column
在后台调用 ALTER TABLE
.来自 MySQL 文档:
change_column
calls ALTER TABLE
under the hood. From the MySQL documentation:
您还可以在 CHANGE
或 MODIFY
操作中使用 FIRST
和 AFTER
来重新排序表中的列.
You can also use
FIRST
andAFTER
inCHANGE
orMODIFY
operations to reorder columns within a table.
请注意,这种方法不适用于 PostgreSQL.(请参阅更改列位置)
Note that this approach doesn't work with PostgreSQL. (see Alter column positions)