More Label Syntaxes

更多标注语法

The heads symbol can be combined with a branch label, in the case that your labeled branch itself breaks off into multiple branches:

heads 符号可以与分支标签结合使用，以防你的标签分支本身分裂成多个分支：

alembic upgrade shoppingcart@heads

Relative identifiers, as introduced in Relative Migration Identifiers, work with labels too. For example, upgrading to shoppingcart@+2 means to upgrade from current heads on “shoppingcart” upwards two revisions:

Relative Migration Identifiers 中介绍的相对标识符也适用于标签。 例如，升级到 shoppingcart@+2 意味着将“shoppingcart”上的当前头像向上升级两个版本：

alembic upgrade shoppingcart@+2

This kind of thing works from history as well:

这也适用于历史：

alembic history -r current:shoppingcart@+2

The newer relnum+delta format can be combined as well, for example if we wanted to list along shoppingcart up until two revisions before the head:

更新的 relnum+delta 格式也可以组合，例如，如果我们想沿着 shoppingcart 列出直到head之前的两个修订：

alembic history -r :shoppingcart@head-2