DESCRIBE EDGE TYPE command

The DESCRIBE EDGE TYPE command returns detailed information about an edge type in a table that consists of the following columns:

Column	Description
property_name	The name of the property of the edge type.
data_type	The value type of the property of the edge type.
multi_edge_key	Indicates whether the property of the edge type is used to create the multi-edge key. If yes, the value is Y; otherwise, the value is empty.
nullable	Indicates whether the property of the edge type can be NULL. Valid values: true and false.
default	The default value of the property of the edge type.

Note

An operation involving a non-default schema or an object in it requires access to the schema, either implicitly or through an explicit USAGE grant, as well as the privilege required for the operation. The schema access check and the privilege check for the requested operation are independent; satisfying one does not satisfy the other. Schema access control does not apply to temporary graphs or built-in procedures and functions. For more information, see Schema access control.

Syntax

diagramsource

describe_edge_type_command

describe_edge_type_command ::=
    ( 'DESCRIBE' | 'DESC' ) 'EDGE TYPE' edge_type_name 'OF' (schema_reference '/')? graph_type_name

Parameters

edge_type_name

The name of the edge type that you want to know details about.

schema_reference

The reference to the path of the schema. Specifically, it specifies the schema path of the graph type that contains the edge type.

Both absolute and relative schema paths can be used in the command. To view detailed information about an edge type in a graph type that resides outside the schema in the current session, the schema path must be specified. For information about setting and viewing the schema for the current session, see SESSION SET and SHOW CURRENT_SCHEMA.

graph_type_name

The name of the graph type that contains the edge type.

Examples

The following examples are based on the example dataset.

Describe an edge type of a graph type in the current schema

DESCRIBE EDGE TYPE Watch OF movie_type

Return:

+---------------+-----------+----------------+----------+---------+
| property_name | data_type | multi_edge_key | nullable | default |
+---------------+-----------+----------------+----------+---------+
| rate          | FLOAT     |                | true     | NULL    |
+---------------+-----------+----------------+----------+---------+

Describe an edge type of a graph type in the specified schema

'''
// Create a schema
CREATE SCHEMA IF NOT EXISTS /my_schema
''' 

'''
// Set the schema for the current session
SESSION SET SCHEMA /my_schema
'''

'''
// Describe an edge type of a graph type in the specified schema
DESCRIBE EDGE TYPE Watch OF /default_schema/movie_type
'''

Return:

+---------------+-----------+----------------+----------+---------+
| property_name | data_type | multi_edge_key | nullable | default |
+---------------+-----------+----------------+----------+---------+
| rate          | FLOAT     |                | true     | NULL    |
+---------------+-----------+----------------+----------+---------+