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
- 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 | |
+-------------------------+-----------+---------+
- 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 | |
+------------------------------+--------------------------------------------------------+---------+
