docs/en/sql-reference/sql-statements/Database/USE.md
USE specifies the active database for your session. You can then perform operations, such as creating tables and executing queries.
USE [<catalog_name>.]<db_name>
| Parameter | Required | Description |
|---|---|---|
| catalog_name | No | The catalog name.<ul><li>If this parameter is not specified, a database in default_catalog is used by default.</li><li>You must specify this parameter when you use a database from an external catalog. For more information, see Example 2.</li><li>You must specify this parameter when you switch databases between different catalogs. For more information, see Example 3.</li></ul>For more information about catalogs, see Overview. |
| db_name | Yes | The database name. The database must exist. |
Example 1: Use example_db from default_catalog as the active database of your session.
USE default_catalog.example_db;
Or
USE example_db;
Example 2: Use example_db from hive_catalog as the active database of your session.
USE hive_catalog.example_db;
Example 3: Switch the active database of your session from hive_catalog.example_table1 to iceberg_catalog.example_table2.
USE iceberg_catalog.example_table2;