How the TO_DAYS() function works in Mariadb?

The TO_DAYS() function in MariaDB is used to convert a date or datetime value into the corresponding day number.

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The TO_DAYS() function in MariaDB is used to convert a date or datetime value into the corresponding day number. The day number represents the number of days since the base date of ‘0000-00-00’ (year 0).

Syntax

The syntax of the MariaDB TO_DAYS() function is as follows:

TO_DAYS(date)
  • date: This is the date or datetime expression to be converted into a day number.

The function returns an integer representing the number of days since the base date ‘0000-00-00’.

Examples

Example 1: Converting a date into a day number

This example demonstrates how to use the TO_DAYS() function to convert a date into a day number.

SELECT TO_DAYS('2023-05-01');

The following is the output:

+-----------------------+
| TO_DAYS('2023-05-01') |
+-----------------------+
|                739006 |
+-----------------------+

In this example, the TO_DAYS() function converts the date ‘2023-05-01’ into the day number 739006, which represents the number of days since the base date ‘0000-00-00’.

Example 2: Converting a datetime into a day number

This example shows how to convert a datetime value into a day number using the TO_DAYS() function.

SELECT TO_DAYS('2023-05-01 12:30:00');

The following is the output:

+--------------------------------+
| TO_DAYS('2023-05-01 12:30:00') |
+--------------------------------+
|                         739006 |
+--------------------------------+

In this example, the TO_DAYS() function ignores the time portion of the datetime value ‘2023-05-01 12:30:00’ and converts only the date part into the day number 739006.

Example 3: Using TO_DAYS() with a table

This example demonstrates how to use the TO_DAYS() function in combination with a table.

DROP TABLE IF EXISTS dates;
CREATE TABLE dates (
    id INT PRIMARY KEY,
    date_value DATE
);
INSERT INTO dates VALUES
    (1, '2023-05-01'),
    (2, '2022-12-31');

SELECT id, date_value, TO_DAYS(date_value) AS day_number
FROM dates;

The following is the output:

+----+------------+------------+
| id | date_value | day_number |
+----+------------+------------+
|  1 | 2023-05-01 |     739006 |
|  2 | 2022-12-31 |     738885 |
+----+------------+------------+

In this example, the TO_DAYS() function is used to convert the date_value column from the dates table into the corresponding day numbers.

Example 4: Using TO_DAYS() with date arithmetic

This example shows how to use the TO_DAYS() function in combination with date arithmetic.

SELECT TO_DAYS('2023-06-01') - TO_DAYS('2023-05-01') AS day_difference;

The following is the output:

+----------------+
| day_difference |
+----------------+
|             31 |
+----------------+

In this example, the TO_DAYS() function is used to convert the dates ‘2023-06-01’ and ‘2023-05-01’ into their corresponding day numbers. Then, the difference between these day numbers is calculated, which gives the number of days between the two dates (31).

Example 5: Using TO_DAYS() with FROM_DAYS()

This example demonstrates how to use the TO_DAYS() function in combination with the FROM_DAYS() function.

SELECT FROM_DAYS(TO_DAYS('2023-05-01'));

The following is the output:

+----------------------------------+
| FROM_DAYS(TO_DAYS('2023-05-01')) |
+----------------------------------+
| 2023-05-01                       |
+----------------------------------+

In this example, the TO_DAYS() function first converts the date ‘2023-05-01’ into its corresponding day number. Then, the FROM_DAYS() function converts this day number back into the original date value ‘2023-05-01’.

The following are some functions related to the MariaDB TO_DAYS() function:

  • MariaDB FROM_DAYS() function is used to convert a day number into a date value.
  • MariaDB DATEDIFF() function is used to calculate the difference between two date or datetime values in days.
  • MariaDB DATE_FORMAT() function is used to format a date or datetime value into a string representation.

Conclusion

The TO_DAYS() function in MariaDB is a useful tool for converting date and datetime values into their corresponding day numbers. It can be used in various scenarios, such as date arithmetic, data processing, and calculations involving dates. By understanding the usage and capabilities of this function, along with related functions, developers can effectively manipulate and work with date data in their MariaDB applications.