DESCRIBE
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Describe the specified table.
Syntax
DESCRIBE [<database_name>.]<table_name>;Remarks
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<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. -
This command can be run on any node (see Node Requirements for SingleStore Commands ).
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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.
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UNI: A unique key is similar to a primary but it can have null values.
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MUL: A multiple key is neither a primary or unique key.
It can have a null value and multiple occurrences of the same value.
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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: March 1, 2023