Postgresql 中文操作指南

DROP COLLATION

删除比较——删除一个比较

DROP COLLATION — remove a collation

DROP COLLATION [ IF EXISTS ] name [ CASCADE | RESTRICT ]

DROP COLLATION 删除先前定义的比较。若要能够删除比较，你必须拥有该比较。

DROP COLLATION removes a previously defined collation. To be able to drop a collation, you must own the collation.

IF EXISTS
- Do not throw an error if the collation does not exist. A notice is issued in this case.
name
- The name of the collation. The collation name can be schema-qualified.
CASCADE
- Automatically drop objects that depend on the collation, and in turn all objects that depend on those objects (see Section 5.14).
RESTRICT
- Refuse to drop the collation if any objects depend on it. This is the default.

删除名为 german 的排序规则：

To drop the collation named german:

DROP COLLATION german;

DROP COLLATION 命令遵循 SQL 标准，除了 IF EXISTS 选项以外，该选项是 PostgreSQL 扩展。

The DROP COLLATION command conforms to the SQL standard, apart from the IF EXISTS option, which is a PostgreSQL extension.