DESCRIBE DATABASE
描述
DESCRIBE DATABASE 语句返回现有数据库的元数据。元数据信息包括数据库名称、数据库注释和文件系统上的数据库位置。如果指定了可选的 EXTENDED 选项，则它会返回基本元数据信息以及数据库属性。DATABASE 和 SCHEMA 可以互换。
语法
{ DESC | DESCRIBE } DATABASE [ EXTENDED ] db_name
参数
-
db_name
指定系统中现有数据库或现有模式的名称。如果该名称不存在，则会引发异常。
示例
-- Create employees DATABASE
CREATE DATABASE employees COMMENT 'For software companies';
-- Describe employees DATABASE.
-- Returns Database Name, Description and Root location of the filesystem
-- for the employees DATABASE.
DESCRIBE DATABASE employees;
+-------------------------+-----------------------------+
|database_description_item| database_description_value|
+-------------------------+-----------------------------+
| Database Name| employees|
| Description| For software companies|
| Location|file:/Users/Temp/employees.db|
+-------------------------+-----------------------------+
-- Create employees DATABASE
CREATE DATABASE employees COMMENT 'For software companies';
-- Alter employees database to set DBPROPERTIES
ALTER DATABASE employees SET DBPROPERTIES ('Create-by' = 'Kevin', 'Create-date' = '09/01/2019');
-- Describe employees DATABASE with EXTENDED option to return additional database properties
DESCRIBE DATABASE EXTENDED employees;
+-------------------------+---------------------------------------------+
|database_description_item| database_description_value|
+-------------------------+---------------------------------------------+
| Database Name| employees|
| Description| For software companies|
| Location| file:/Users/Temp/employees.db|
| Properties|((Create-by,kevin), (Create-date,09/01/2019))|
+-------------------------+---------------------------------------------+
-- Create deployment SCHEMA
CREATE SCHEMA deployment COMMENT 'Deployment environment';
-- Describe deployment, the DATABASE and SCHEMA are interchangeable, their meaning are the same.
DESC DATABASE deployment;
+-------------------------+------------------------------+
|database_description_item|database_description_value |
+-------------------------+------------------------------+
| Database Name| deployment|
| Description| Deployment environment|
| Location|file:/Users/Temp/deployment.db|
+-------------------------+------------------------------+