Syntax

BLOB[(M)]

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

In 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

See Also

• BLOB and TEXT Data Types
• Data Type Storage Requirements
• Oracle mode from MariaDB 10.3