# 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.

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).

## Related Functions

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.