DESCRIBE

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.
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 | | +------------+---------------+------+-----+---------+-------+

DESCRIBE

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Syntax

Remarks

Examples

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