Oracle教程 2023-03-20

Oracle 视图 ALL_HIER_CLASS 官方解释，作用，如何使用详细说明

ALL_HIER_CLASSES视图是显示所有联接非叶层级分类的视图，该视图只在数据库中包含 DBMS_HIERARCHY_OBJECTS 的客户端机器上有效。

ALL_HIER_CLASSES 视图包含以下列:

HIER_CLASS_ID：此列中存储的是层级类的唯一标识符。

PARENT_HIER_CLASS_ID：此列中存储的是父层级类的唯一标识符，从而定义了每个层级的父类。

OBJECT_NAME: 此列中存储的是对象的名称，用于将子对象和父类连接在一起。

OBJECT_TYPE：此列中存储的是对象的类型。

HIERARCHY_TYPE：此列中存储的是层级类的类型，它可以是“常规”、“普通”或“并行”结构。

OBJECT_INSTANCE：此列存储的是当前层次类的唯一标识符，它可以用于链接联接层次。

使用ALL_HIER_CLASSES视图可以结合其他视图或表查询，用于检索和检查分层数据。比如，可以查询ALL_HIER_CLASSES视图并检查特定层次类的父类ID，并使用它来查询特定父类的其他详细信息。

ALL_HIER_CLASS describes the classifications of the hierarchies accessible to the current user.

Related Views

DBA_HIER_CLASS describes the classifications of all hierarchies in the database.
USER_HIER_CLASS describes the classifications of the hierarchies owned by the current user. This view does not display the OWNER column.

Column	Datatype	NULL	Description
`OWNER`	`VARCHAR2(128)`	`NOT NULL`	Owner of the hierarchy
`HIER_NAME`	`VARCHAR2(128)`	`NOT NULL`	Name of the hierarchy
`CLASSIFICATION`	`VARCHAR2(128)`		Classification associated with the hierarchy
`VALUE`	`CLOB`		Value of the classification or NULL if not specified
`LANGUAGE`	`VARCHAR2(64)`		`NLS_LANGUAGE` value associated with the classification or NULL if not specified
`ORDER_NUM`	`NUMBER`	`NOT NULL`	Order of the classification in the list of classifications associated with the hierarchy
`ORIGIN_CON_ID`	`NUMBER`		The ID of the container where the data originates. Possible values include: `0`: This value is used for rows in non-CDBs. This value is not used for CDBs. n: This value is used for rows containing data that originate in the container with container ID n (n = 1 if the row originates in root).