DESCRIBE TABLE

DESCRIBE [TABLE] [db.]table describes the table structure in the db or the current database in-use.

Examples

Describes the table monitor:

sql

1. DESCRIBE TABLE monitor;

or

sql

1. DESCRIBE monitor;

Output:

sql

1. +--------+----------------------+------+------+---------------------+---------------+
2. | Column | Type                 | Key  | Null | Default             | Semantic Type |
3. +--------+----------------------+------+------+---------------------+---------------+
4. | host   | String               | PRI  | YES  |                     | TAG           |
5. | ts     | TimestampMillisecond | PRI  | NO   | current_timestamp() | TIMESTAMP     |
6. | cpu    | Float64              |      | YES  | 0                   | FIELD         |
7. | memory | Float64              |      | YES  |                     | FIELD         |
8. +--------+----------------------+------+------+---------------------+---------------+
9. 4 rows in set (0.00 sec)

It produces the table structure:

  • Column: the column names
  • Type: the column data types
  • Key: PRI means the column is in the primary key constraint.
  • Null: YES means nullable, otherwise NO
  • Default: default value or expression of the column
  • Semantic Type: This column represents the semantic type, corresponding to TAG, FIELD or TIMESTAMP in the data model.