Source: https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/data-admin/describe/describe-edge-type/
Documentation version: v5.3.2

# 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](https://dev-docs.nebula-graph.io/v5.3.2/server-admin/authorization/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](https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/sessions/set/) and [SHOW CURRENT_SCHEMA](https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/data-admin/show/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](https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/overview/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    |
+---------------+-----------+----------------+----------+---------+

````