Description

By using the DESC or DESCRIBE statement, users can view detailed structural information of a specified external table in the Lakehouse database, including field names, data types, whether null values are allowed, key information, and default values.

Syntax

DESC[RIBE] [EXTENDED] table_name;

Parameter Description

• DESC[RIBE]: DESC and DESCRIBE can be used interchangeably, both representing the command to describe the table structure.
• EXTENDED: (Optional) Adding this keyword will display more extended information, such as file location information.
• table_name: Specifies the name of the external table whose structure needs to be viewed. Supports viewing EXTERNAL TABLE, VIEW, DYNAMIC TABLE, and materialized view.

Example

1. View the basic structure of an external table:

   DESC my_external_table; +-------------------------+-----------+---------+ | column_name | data_type | comment | +-------------------------+-----------+---------+ | id | int | | | name | string | | | dt | string | | | # Partition Information | | | | # col_name | data_type | comment | | dt | string | | +-------------------------+-----------+---------+

2. View the Extended Structure Information of External Tables:

   DESC EXTENDED my_external_table; +------------------------------+--------------------------------------------------------+---------+ | column_name | data_type | comment | +------------------------------+--------------------------------------------------------+---------+ | id | int | | | name | string | | | dt | string | | | # Partition Information | | | | # col_name | data_type | comment |

| dt | string | | | | | | | # detailed table information | | | | schema | public | | | name | my_external_table | | | creator | UAT_TEST | | | created_time | 2024-05-24 14:04:17.517 | | | last_modified_time | 2024-05-24 14:04:17.537 | | | comment | edelta-external | | | properties | () | | | external | true | | | type | TABLE | | | clustered_keys | RANGE (__dt) | | | bucket_count | 0 | | | format | delta | | | location | "oss://function-compute-my1/delta-format/uploaddelta/" | | | connection | ql_ws.oss_delta | | | statistics | NULL rows NULL bytes | |

+------------------------------+--------------------------------------------------------+---------+