DESCRIBE

Warning

SingleStore 9.0 gives you the opportunity to preview, evaluate, and provide feedback on new and upcoming features prior to their general availability. In the interim, SingleStore 8.9 is recommended for production workloads, which can later be upgraded to SingleStore 9.0.

Syntax

DESCRIBE [<database_name>.]<table_name>;

Remarks

<table_name> is the name of a table in a database.
<database_name> is the name of a database. Not needed if the table exists in the current database.
This command can be run on any node (see Node Requirements for SingleStore Commands ).
key has three possible values, primary (PRI), unique (UNI), and multiple (MUL).
- PRI: A primary key can be one or more columns, but cannot be null.
- UNI: A unique key is similar to a primary but it can have null values.
- MUL: A multiple key is neither a primary or unique key. It can have a null value and multiple occurrences of the same value.

Warning

When setting a unique or primary key you need to have a shard key. Otherwise you will receive an error.

Examples

SQL

DESCRIBE test;

+-------+-------------+------+-----+---------+----------------+
| Field | Type        | Null | Key | Default | Extra          |
+-------+-------------+------+-----+---------+----------------+
| id    | int(11)     | NO   | PRI | NULL    | auto_increment |
| v     | varchar(10) | NO   |     | NULL    |                |
+-------+-------------+------+-----+---------+----------------+

DESCRIBE memsql_demo.customer;

+------------+---------------+------+-----+---------+-------+
| Field      | Type          | Null | Key | Default | Extra |
+------------+---------------+------+-----+---------+-------+
| custkey    | int(11)       | NO   | PRI | NULL    |       |
| name       | varchar(25)   | NO   |     | NULL    |       |
| address    | varchar(40)   | NO   |     | NULL    |       |
| nationkey  | int(11)       | NO   | MUL | NULL    |       |
| phone      | char(15)      | NO   |     | NULL    |       |
| acctbal    | decimal(15,2) | NO   |     | NULL    |       |
| mktsegment | char(10)      | NO   |     | NULL    |       |
| comment    | varchar(117)  | NO   |     | NULL    |       |
| zip2       | binary(5)     | YES  |     | NULL    |       |
| balance    | double        | YES  |     | NULL    |       |
+------------+---------------+------+-----+---------+-------+