BLOB
Syntax
BLOB[(M)]
Contents
Description
A BLOB
column with a maximum length of 65,535
(216 - 1
) bytes. Each
BLOB
value is stored using a two-byte length prefix that indicates the
number of bytes in the value.
An optional length M
can be given for this type. If this is done,
MariaDB creates the column as the smallest BLOB
type large enough to
hold values M
bytes long.
BLOBS can also be used to store dynamic columns.
Before MariaDB 10.2.1, BLOB
and TEXT
columns could not be assigned a DEFAULT value. This restriction was lifted in MariaDB 10.2.1.
Indexing
MariaDB starting with 10.4
From MariaDB 10.4, it is possible to set a unique index on a column that uses the BLOB
data type. In previous releases this was not possible, as the index would only guarantee the uniqueness of a fixed number of characters.
Oracle Mode
MariaDB starting with 10.3
In Oracle mode from MariaDB 10.3, BLOB
is a synonym for LONGBLOB
.