MariaDB DEFAULT() Function

In MariaDB, DEFAULT() is a built-in function that returns the default value of a given table column.

MariaDB DEFAULT() syntax

Here is the syntax of the MariaDB DEFAULT() function:

DEFAULT(column_name)

Parameters

column_name

Optional. a column name.

Return value

MariaDB DEFAULT() function returns the default value of the specified column.

This function will report an error if the specified column does not have a default value defined.

MariaDB DEFAULT() Examples

To demonstrate the usages of the DEFAULT() function, let us create a table named test_default using the following statement:

CREATE TABLE test_default (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(255) NOT NULL,
    default_int INT NOT NULL DEFAULT 0,
    default_date DATE NOT NULL DEFAULT (CURRENT_DATE)
);

Here, we create a table with 4 columns, where the following 2 columns have default values:

• The default_int column has a default value 0.
• The default_date column has a default value produced by (CURRENT_DATE).

Then, let’s insert some rows:

INSERT INTO test_default (name, default_int)
VALUES ('Tom', 1);

Let’s look at all the rows in the table:

SELECT * FROM test_default;

+----+------+-------------+--------------+
| id | name | default_int | default_date |
+----+------+-------------+--------------+
|  1 | Tom  |           1 | 2023-02-03   |
+----+------+-------------+--------------+

Now, let’s look at the default value of the default_int column using the DEFAULT() function:

SELECT DEFAULT(default_int) FROM test_default;

+----------------------+
| DEFAULT(default_int) |
+----------------------+
|                    0 |
+----------------------+

The default value of default_int is 0, which is also shown in the output of the above statement.

Let’s see what happens when we call DEFAULT() on the name column:

SELECT DEFAULT(name) FROM test_default;

ERROR 1364 (HY000): Field 'name' doesn't have a default value

The DEFAULT() function reported an error because we did not define a default value for the name column.

Let’s see what happens when we call DEFAULT() on the default_date column:

SELECT DEFAULT(default_date) FROM test_default;

+-----------------------+
| DEFAULT(default_date) |
+-----------------------+
| 2023-02-03            |
+-----------------------+

Conclusion

In MariaDB, DEFAULT() is a built-in function that returns the default value of a given table column.