How the BIT_OR() function works in Mariadb?

MariaDB’s BIT_OR() function is used to perform a bitwise OR operation on all bits in a given expression.

Posted on

The MariaDB BIT_OR() function is used to perform a bitwise OR operation on all bits in a given expression. This function is commonly used in situations where you need to combine multiple binary values or flags into a single value.

Syntax

The syntax for the MariaDB BIT_OR() function is as follows:

BIT_OR(expr)

This function takes an expression expr as an argument and returns the result of the bitwise OR operation.

Examples

Example 1: Basic Usage

To demonstrate the basic usage of BIT_OR(), consider the following SQL statement:

SELECT BIT_OR(5);

+-----------+
| BIT_OR(5) |
+-----------+
|         5 |
+-----------+

The output is 5 because the bitwise OR of 5 (which is 101 in binary) with itself is 101.

Example 2: OR Operation with Multiple Numbers

This example shows how BIT_OR() operates with multiple numbers:

SELECT BIT_OR(5 | 2);

+---------------+
| BIT_OR(5 | 2) |
+---------------+
|             7 |
+---------------+

The output is 7 because the bitwise OR of 5 (101 in binary) and 2 (010 in binary) is 111.

Example 3: Using with Tables

If we need to use BIT_OR() with table data, we can create a table and insert values as follows:

DROP TABLE IF EXISTS example;
CREATE TABLE example (a INT);
INSERT INTO example VALUES (5), (2), (1);

Now, applying BIT_OR():

SELECT BIT_OR(a) FROM example;

+-----------+
| BIT_OR(a) |
+-----------+
|         7 |
+-----------+

The output is 7 because the bitwise OR of 5 (101), 2 (010), and 1 (001) is 111.

Example 4: OR Operation with No Rows

Here’s what happens when there are no matching rows:

SELECT BIT_OR(NULL);

+--------------+
| BIT_OR(NULL) |
+--------------+
|            0 |
+--------------+

When no rows match, BIT_OR() returns 0.

Example 5: OR Operation with Large Numbers

Let’s see how BIT_OR() works with larger numbers:

SELECT BIT_OR(1024 | 2048);

+---------------------+
| BIT_OR(1024 | 2048) |
+---------------------+
|                3072 |
+---------------------+

The output is 3072 because the bitwise OR of 1024 (10000000000 in binary) and 2048 (100000000000 in binary) is 3072 (110000000000 in binary).

Here are a few functions related to MariaDB’s BIT_OR():

  • MariaDB’s BIT_AND() function is used to perform a bitwise AND operation on all bits in an expression.
  • MariaDB’s BIT_XOR() function is used to perform a bitwise XOR operation on all bits in an expression.
  • MariaDB’s BIT_COUNT() function is used to count the number of bits that are set in an expression.

Conclusion

The BIT_OR() function in MariaDB is a versatile tool for combining binary values across multiple rows. It is particularly useful in scenarios where you need to aggregate binary flags or permissions. Understanding how to use BIT_OR() and related functions can be very beneficial for database operations involving binary data manipulation.