Important
Helios features are now enabled during weekly update windows and are no longer directly tied to SingleStore engine releases. Refer to the release notes to view the latest features available in your Helios cluster.
DESCRIBE
On this page
The DESCRIBE command describes the specified table.
Syntax
DESCRIBE [<database_name>.]<table_name>;Remarks
-
<table_is the name of a table in a database.name> -
<database_is the name of a database.name> Not needed if the table exists in the current database. -
keyhas 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.
Examples
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 | |
+------------+---------------+------+-----+---------+-------+Last modified: