DESCRIBE

使用 DESCRIBE 命令查看指定表、source、sink、视图或物化视图中的列。

DESCRIBE 是 SHOW COLUMNS 的快捷方式。

tip

DESCRIBE 还会列出表或物化视图的索引，而 SHOW COLUMNS 则不会。

句法

DESCRIBE relation_name;

参数

参数或子句	描述
relation_name	要列出其列的表、source、sink、视图或物化视图。

示例

准备工作

CREATE TABLE customers (
  customer_id BIGINT PRIMARY KEY,  
  name VARCHAR,
  email VARCHAR
);
COMMENT ON COLUMN customers.customer_id IS '每个用户的唯一标识符';
COMMENT ON COLUMN customers.name IS '用户的姓名';
COMMENT ON COLUMN customers.email IS '用户的电子邮件地址';
COMMENT ON TABLE customers IS '所有用户数据';
CREATE INDEX idx_customers_email ON customers(email);

创建表、列和索引并为其添加注释后，可以使用 DESCRIBE 命令查看所有结构信息。

输出

DESCRIBE customers;

| Name                | Type                                                                  | Is Hidden | Description                         |
| ------------------- | --------------------------------------------------------------------- | --------- | ----------------------------------- |
| customer_id         | bigint                                                                | false     | Unique identifier for each customer |
| name                | character varying                                                     | false     | Name of the customer                |
| email               | character varying                                                     | false     | Email address of the customer       |
| primary key         | customer_id                                                           |           |                                     |
| distribution key    | customer_id                                                           |           |                                     |
| idx_customers_email | index(email ASC, customer_id ASC) include(name) distributed by(email) |           |                                     |
| table description   | customers                                                             |           | All customer records                |