DESCRIBE SCHEMA

  • 项目

适用于：check marked yes Databricks SQL check marked yes Databricks Runtime

返回现有架构的元数据。 元数据信息包括架构的名称、注释和文件系统上的位置。 如果指定了可选的 EXTENDED 选项，则还会返回架构属性。

虽然使用 SCHEMA 和 DATABASE 是可互换的，但最好使用 SCHEMA。

语法

{ DESC | DESCRIBE } SCHEMA [ EXTENDED ] schema_name

parameters

  • schema_name：系统中现有架构的名称。 如果该名称不存在，则会引发异常。

示例

-- Create employees SCHEMA
> CREATE SCHEMA employees COMMENT 'For software companies';

-- Describe employees SCHEMA.
-- Returns Database Name, Description and Root location of the filesystem
-- for the employees SCHEMA.
> DESCRIBE SCHEMA employees;
 database_description_item    database_description_value
 ------------------------- -----------------------------
             Database Name                     employees
               Description        For software companies
                  Location file:/you/Temp/employees.db

-- Create employees SCHEMA
> CREATE SCHEMA employees COMMENT 'For software companies';

-- Alter employees schema to set DBPROPERTIES
> ALTER SCHEMA employees SET DBPROPERTIES ('Create-by' = 'Kevin', 'Create-date' = '09/01/2019');

-- Describe employees SCHEMA with EXTENDED option to return additional schema properties
> DESCRIBE SCHEMA EXTENDED employees;
 database_description_item                    database_description_value
 ------------------------- ---------------------------------------------
             Database Name                                     employees
               Description                        For software companies
                  Location                 file:/you/Temp/employees.db
                Properties ((Create-by,kevin), (Create-date,09/01/2019))

-- Create deployment SCHEMA
> CREATE SCHEMA deployment COMMENT 'Deployment environment';

-- Describe deployment.
> DESCRIBE SCHEMA deployment;
 database_description_item database_description_value
 ------------------------- ------------------------------
             Database Name                     deployment
               Description         Deployment environment
                  Location file:/you/Temp/deployment.db